Q-1 what is function? Explain its components and function ... · return value data type. Function Call Causes the function to execute. Function Definition The function itself contains

MCA Semester – I 610001 - Fundamentals of Programming (FOP)

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Q-1 what is function? Explain its components and function types in c?

Explain formal parameter and actual parameters?

A function is basically a self – contained block of program statements that

performs a particular task in program.

It is basically a group of statements used to perform a specific task.

Actually the concept of function is basically the concept called sub-program.

Why they are require?

In a program there are some situation where it is required to execute a

series of program statements, repeatedly, n times.

So at that time without writing the same code at as many places in same

program we can write it as a block of program and can execute it whenever it

required in the program.

The above situation can be expressed as follows:

Here figure (I) shows a program not using a function (II) shows program

using one function call many times.

If a program doesn’t uses a function than a program length would be larger

which is difficult for reading and locating an errors.



C divides the entire concept of programming to a combination of functions.

C has no procedures, only functions.

A function can be declared in C program using following construct :

Return_type function_name (datatype var1, datatype var2, … , datatype

varN);

{

Executable statement 1 ;

Executable statement 2 ;

Return expr;

}

The above declaration indicates that

1. Function_name : - It is the name of function.

2. Return_type : It is the data type which type value the function can return.

3. Return: It returns the value to the calling function which is of type

Return_type.

Any no. of variables can be passed as its argument when the function is

being called. Also any no. of statements can resides between two

parentheses {}.

� Components of a function :

Components Purpose

Function prototype Declaration Specifies function name, arg. Type and

return value data type.

Function Call Causes the function to execute.

Function Definition The function itself contains the lines of

code that is to be executed.

� Function prototype declaration :

Before a function is used, C must know the parameter types the

function expects to receive and the data type to returns. Therefore a user

defined function should be normally declared before it use to allow the

compiler to perform type checking of its arguments used in function call.



• The general form of function prototype declaration :

Return_type function_name (datatype var1, datatype var2, … , datatype

varN);


1. Function_name : - It is the name of function.

2. Return_type : It is the data type which type value the function can return.

� Function Call :

All functions , within the standard library or user-written, are called from

within the main() function.

The function call statement invokes the function , which means the

program control passes to that of the function. Once the function completes its

task, the program control is passed back to the calling function.

The general form for function call statement :

Function_name(variable1 , variable2, …., variableN);


1. Variable : It indicates the arguments to be passes to the function.

� Function Definition :

The function definition section defines the collection of statements to be

executed whenever the function is to be called.

It consist of the function header and a function body, which is a block of

code enclosed in parentheses

• The general form of function definition :

return_type function_name (datatype var1 , datatype varN)

{

local variable declaration ;

statements ;

return expr;

}



� Formal parameter & Actual Parameter :

A function will carry out its task whenever it accessed from some portion of a

program. Generally a function will process information passed to it from the

calling statement of a program and return a single value.

Information will passes to the function via special identifiers or variables

called arguments or actual arguments and returned with return statement.

A parameter or variable defined in function definition or function

prototype is called a formal parameter.

For example.



Question: Explain following Function with Syntax and Example.

(1) strcat ( )

Syntax:

char *strcat(char *dest, const char *src);

The strcat( ) function concatenates a copy of str2 to str1 and terminates

str1 with a null. The null terminator originally ending str1 is overwritten

by the first character of str2.

The strcat( ) function returns str1.

Example:

char *s1=”Good ”,*s2=”Morning”;

strcat(s1,s2);

printf(“%s”,s1);

Output:

Good Morning

(2) strcpy( )

Syntax:

char *strcpy(char *str1, const char *str2);

The strcpy( ) function copies the contents of str2 into str1. str2 must be a

pointer to a null terminated string.

The strcpy( ) function returns a pointer to str1.

Example:

Char *s1=”Good ”,*s2=”Morning”;

strcpy(s1,s2);

printf(“%s”,s1);

Output:

Morning

(3) strcmp( )

Syntax:

int strcmp(const char *str1, const char *str2);

The strcmp( ) function compares two strings and returns an integer based

on the outcome as shown here:



Value Meaning

Less than zero str1 is less than str2

Zero str1 is equal to str2

Greater than zero str1 is greater than str2

Example:

char *s1=”Good”,*s2=”Goood”;

If(strcmp(s1,s2) == 0)

{

printf(“String is Equal”);

}

else

{

printf(“String is not Equal”);

}

Output:

String is Equal

(4) strlen( )

Syntax:

size_t strlen(const char *str);

The strlen( ) function returns the length of the null-terminated string

pointed to by str. The null terminator is not counted.

Example

The following code fragment prints 5 on the screen:

printf("%d", strlen("hello"));

(5) getch( )

Syntax:

int getch(void);

getch reads a single character directly from the keyboard, without echoing

to the screen.

getch() return the character read from the keyboard.

Example



char ch;

ch=getch();

(6) getche( )

Syntax:

int getche(void);

getche reads a single character from the keyboard and echoes it to the

current text window, using direct video or BIOS.

getche() return the character read from the keyboard.

Example

char ch;

ch=getche();

(7) getchar( )

Syntax:

int getchar(void);

getchar() is implemented in such a way that it buffers input an integer is

passed. So, this is called line buffered input until you have press ENTER.

Return Value:

On success,getchar returns the character read, after converting it to an int

without sign extension.

On error return EOF.

Example

char ch;

ch=getchar();

(8) fseek( )

fseek() Repositions the file pointer of a stream

You can perform random read and write operations using the C I/O system

with the help of fseek( ),which sets the file position indicator.



Syntax:

int fseek(FILE *fp, long int numbytes, int origin);

Argument What It Is/Does

*fp File pointer

num_bytes Number of bytes from origin

Origin Origin Meaning Value

SEEK_SET Beginning of file 0

SEEK_CUR Current position 1

SEEK_END End of file 2

fseek( ) function returns zero when successful and a nonzero value if an

error occurs.

Example

FILE *fp;

fp=fopen(“D:/student.txt”);

fseek(*fp,0L,SEEK_SET);

(9) ftell( )

Returns the current file pointer

You can determine the current location of a file using ftell( ).

Syntax:

long int ftell(FILE *fp);

It returns the location of the current position of the file associated with fp.

If a failure occurs, it returns –1.

Example:

FILE *fp;

Fp=fopen(“D:/student.txt”);

int i;

i=ftell(fp);



(10) feof( )

Syntax:

int feof(FILE *stream);

The feof( ) function determines whether the end of the file associated with

stream has been reached.

A nonzero value is returned if the file position indicator is at the end of the

file; zero is returned otherwise.

Example

This code fragment shows one way to read to the end of a file:

Assume that fp has been opened for read operations.

while(!feof(fp))

{

getc(fp);

}

(11) fread( )

fread( ) functions allow the reading of blocks of any type of data.

Syntax:

size_t fread(void *buffer, size_t num_bytes, size_t count, FILE *fp);


*buffer Points to a block into which data is read

num_bytes Length of each item read, in bytes

Count Number of items read

*fp Specifies file pointer

The fread( ) function returns the number of items read.

(12) fwrite( )

fwrite( ) functions allow the writing of blocks of any type of data.

Syntax:

size_t fwrite(const void *buffer, size_t num_bytes, size_t count, FILE *fp);


*buffer Pointer to any object; the data written begins at ptr



num_bytes Length of each item of data

count Number of data items to be appended

*fp Specifies file pointer

The fwrite( ) function returns the number of items written.

(13) sizeof( )

Syntax:

sizeof <expression>

sizeof ( <type> )

sizeof is a unary compile-time operator that returns the length, in bytes, of

the variable or parenthesized type specifier that it precedes.

Example:

double f;

printf("%d ", sizeof(f));

printf(''%d", sizeof(int));



Question: Explain storage class in c.

Answer:

• In c, the variables are declared by the type of data they can hold.

• The name of variable is associated with a memory location within the

computer where the value assigned to the variable is stored in the form of

bits.

• During the execution of program these variable may be stored in register of

CPU or the primary memory of the computer.

• To indicate where the variable would be stored, how long they would exist,

what would be their region of existence and what its default value, all things

depends on storage class.

• The prototype of storage class specifier is:

<storage_class_specifier> <data_type> <variable_name>;

• C provides four types of storage class.

1. Automatic

2. External

3. Register

4. Static

1. Automatic storage class specifier:

• By, default all variable declared within the body of any function are of any

function are automatic.

• The keyword auto is used in the declaration of a variable to explicitly specify

its storage class.

• Their region of use in limited within the function body and when the

function completes its specific task and

• These variables stored in primary memory of the computer and behave as

local variable of the function.

• The default value held within these variables is garbage.

• Syntax:

auto <data_type> <variable_name>;

• Example:

auto char any_alpha;

auto int any_number;

auto float any_decimal;



2. External storage class specifier:

• A program in c, particularly when it is large can be broken up in to

smaller program.

• After compiling these, each program file can be joined together to from

the large program.

• These small programs module that combine together may need some

variables that are used by all of them.

• In c such a provision can be made by specifying these variables

accessible to all the small program modules as an external storage class

variable.

• These variables are global to all small programs that are formed as

separate file.

• The key word declaring such global variable is extern.

• These variables remain as long as the program is in execution.

• These variable stored in primary memory of computer.

• Their default value is Zero.

• Syntax:

extern <data_type> <variable_name>;

• Example:

extern int i ;

3. Register storage class specifier:

• Variable stored in register of CPU are accessed in much lesser time then

those stored in the primary memory.

• To allow the fastest access time for variables the register storage class

specifier is used.

• The keyword for this storage class is register.

• These variables are stored in some register of CPU.

• The default value of this variable is garbage.

• The existence of the register specified variable are restricted within the

region of function or a block where it has been declared and exist as long

as the function or block remains active.

• Syntax:

register <data_type> <variable_name>;

• Example:

register int i;



4. Static storage class specifier:

• The use of static storage class specifier makes a variable a permanent

variable within a specified region.

• Two kinds of variable are allowed to be specified as static variable:

1. Local variable.

2. Global variable.

• The default value of static variable is Zero.

• The keyword for this storage class is static.

• The variable is usable with in function or block where it is declared and

preserves its previous value held by it between function calls or between

block re-entries.

• Syntax:

static <data_type> <variable_name>;

• Example:

static int i ;



Question: Explain dynamic memory allocation functions.

Answer:

• A dynamic memory allocation uses function to get memory dynamically.

• If functions are used to get memory dynamically and the values returned by

these function are assigned to pointer variables such assignments are known

as dynamically memory allocation.

• Memory assigned during runtime.

• C provide four types of dynamic memory allocation function:

1. malloc()

2. calloc()

3. realloc()

4. free()

1. malloc ():

• malloc function useful to allocate memory dynamically.

• This function requests a contiguous block of memory of the given size in heap.

• malloc() return a pointer to the heap block or NULL if request is not satisfied.

• Syntax:

void * malloc( size_t size);

• The type size_t is essentially an unsigned long that indicates how large a block

the caller would like measured in bytes.

• Because of block pointer returned by malloc () is a void *, a type cast will be

required when storing the void pointer in to regular typed pointer.

• Example:

Int *ip;

Ip=(int *) malloc (sizeof(int));

2. calloc ():

• Calloc () works like malloc () functions.

• But initialize the memory to zero if possible.

• Syntax: void * calloc(size_t count,size_t eltsize);

• This function allocates a block enough to contain an array of count elements.

• Each of element size is eltsize.

• Its content is cleared to zero before calloc returns.

• Example:

int *ip,count;

ip= (int *) calloc (count, sizeof (int));



3. realloc():

• realloc() function take an existing heap block and try to reallocate it to a heap

block of given size which may be larger or smaller than the original size of

block.

• This function returns a pointer to the new block or NULL if the reallocation was

unsuccessful.

• realloc() takes care of moving the bytes from the old block to new block.

• Syntax: void * realloc(void *block,size_t size);

• Example:

int *ip;

ip=(int *) realloc (np,200*sizeof(int));

• Memory reallocation has succeeded and np might be set to what is returned.

4. free():

• Free() function takes a pointer to a heap block earlier allocated by malloc ()

and returns that block to the heap block to the heap for reuse.

• After the free() the user should not access any part of the block or assume that

the block is valid memory.

• A block should not feed a second time.

• Syntax:

void free(void * block);

• Example:

int * ip;

ip= (int *) malloc (sizeof(int));

free (ip);



Question: What is an array? How it differ from an ordinary variable?

Explain the procedure to initialize one-dimensional and two Dimensional

arrays.

Answer :

An Array is the collection of an element that can share same name

OR

An Array is a derived data type variable that holds multiple elements which has

the same data type.

Difference between Array and ordinary variable :

• A variable is a reference to a single object (often a number, character, or

string of characters). An array is a reference to a contiguous block of

memory in which zero or more individual objects.

• Array is the set of a multiple values where as variable can store single

value at a time.

• The difference between the definition of array and ordinary variable is the,

array is always declared, initialized, and accessed using subscript whereas

ordinary variable do not have any subscript.

• The syntax for ordinary variable definition is data_type v1, v2, ….; And the

syntax for array variable is data_type v1[N1],v2[N2],…; where v1,v2 are

name of variable and N1, N2 are the integer constants indicating the

maximum size of array.

Procedure to initialize one-dimensional:

• We can initialization the element of array in the same way as the ordinary

variable When declaring a regular array of local scope (within a function,

for example), if we do not specify otherwise, its elements will not be

initialized to any value by default, so their content will be undetermined

until we store some value in them. Array are automatically initialized with

their default values, which for all fundamental types this means they are

filled with zeros.

• Declare an array, we have the possibility to assign initial values to each

one of its elements by enclosing the values in braces { }.

For example:

int billy[5] = { 16, 2, 77, 40, 12071 };

• An array index will always start with zero (0) ,in memory it initialize with

the continues memory location as given below.

MCA Semester – I

Department of MCA, B. H. Gardi College of Engineering & Technology, Rajkot

This declaration would have created an array like this:

• The amount of values between

number of elements that we declare for the array between square brackets

[ ]. For example, in the example of array

elements and in the list of initial values within braces

5 values, one for each element.

• After this declaration, array

initialization values.

Procedure to initialize 2

• Like the one-dimensional array two

by following their declaration with a list of initial enclosed in branch.

int table[2][3]={0,0,0,1,1,1};

• Two dimensional array can we initializing with the row and column in

first dimension total no of row and second dimensio

column

• Initializes the element of the first row to zero and the second row to 1

then initialization is done row by row. an above statement can be

equivalently written as

int table [2][3]={

OR

int table [2][3]={{0,0,0} {1,1,1}};

Initialization in the memory of two

610001 - Fundamentals of Programming (FOP)

Department of MCA, B. H. Gardi College of Engineering & Technology, Rajkot

This declaration would have created an array like this:

The amount of values between braces { } must not be larger than the


. For example, in the example of array arr we have declared that it has 5

elements and in the list of initial values within braces { } we hav

values, one for each element.

After this declaration, array arr would be 5 ints l, since we have provided 5

initialization values.

Procedure to initialize 2-dimensional:

dimensional array two- dimensional array may be initialize


nt table[2][3]={0,0,0,1,1,1};

Two dimensional array can we initializing with the row and column in

first dimension total no of row and second dimension total number of

Initializes the element of the first row to zero and the second row to 1


lently written as

nt table [2][3]={

{0,0,0}

{1,1,1}

};

OR

nt table [2][3]={{0,0,0} {1,1,1}};

Initialization in the memory of two-dimension array:

Fundamentals of Programming (FOP)


must not be larger than the


we have declared that it has 5

we have specified

would be 5 ints l, since we have provided 5

dimensional array may be initialized


Two dimensional array can we initializing with the row and column in

n total number of

Initializes the element of the first row to zero and the second row to 1




• Initialization in the memory of two-dimension array in the continues

memory allocation as under



Question: Explain Bit-Field in Brief.

• There are mainly two ways of manipulating the bits in C.

1. Bit wise operators

2. Bit Fields

• One of the ways consist of using bitwise operators. The other way consist

of using bitfield in which the definition and the access method are based

on structure.

The general format for declaring bit-fields using a structure is as

follows:

Struct bitfield_name

{

Unsigned int member1 : bit_width1 ;

Unsigned int member2 : bit_width2;

…..

Unsigned int memberN : bit_widthN;

}variable1,variable2,…,variable;

In above construct, the declaration of variable is optional. We can

individually create the variables for the structure by:

struct bitfield_name Variable1, Variable 2, …. , VariableN;

In above structure of bit field each bitfield , for example , ‘unsigned int

member 1 : bit_width1’, is an integer that has a specified bit width.

By this technique the exaxt number of bits required can be specified. So a

whole world is not required to hold a field.



These will result in saving bits within a word rather than the whole words

to be considered. The use of bitfields may save some memory against the

variables which can have either 1 or 0 characters.

This idea directly motivates the consept of packed fields and operation on

individual bits.

For Ex., consider the following bit field structure :

Struct test

{

Unsigned tx : 2 ;

Unsigned rx : 2 ;

Unsigned chk_sum : 3 ;

Unsigned p : 1 ;

}status_byte;

These construct declares a structure that has

1. A variable name , status_byte , containing four unsigned bitfields.

2. The number following the colon is the field width. Field variables may be

assigned values. The value assigned to a field must not be greater than its

maximum storable value.

3. Individual fields are referenced as though they are structure members.

Like ,

chk_sum = 6 ;

i.e. the above statement will sets the bits in the chk_sum as 110.

However, some extra instructions will be required to perform all

necessary packing and unpacking of bits. So bit-fields are very rarely used

in practice.



Question: Explain Bitwise Operator in Brief.

• In C there are two ways of manipulating the data bits

1. By Bitwise Operator

2. Bit - Field

• C has a distinction of supporting some special operators known as Bitwise

Operators for manipulating the data at bit-lewel.

• Bitwise operators except their operands to be an integer values and

treated them as a bit sequence.

• These variables are basically used for reseting the bits or shifting them

right or shifting them left.

• Bit wise operators may not be applied to float or doubles.

The following table shows the commonly available bit wise operators :

Operator Description

& Bitwise AND

| Bitwise OR

^ Bitwise XOR

<< Bitwise Shift Left

>> Bitwise Shift Right

~ Bitwise Negation

1. & - Bitwise AND :-

The bitwise AND compares the corresponding bits of its operands

and produces a 1 when both bits are 1 otherwise produces 0.

Variable Decimal

Equivalent B3 B2 B1 B0

X 12 1 1 0 0

Y 10 1 0 1 0

Z = x & y 8 1 0 0 0

2. | - Bitwise OR :-

The bitwise OR compares the corresponding bits of its operands and

produces a 0 when both bits are 0, and 1 otherwise.



Variable Decimal


X 12 1 1 0 0

Y 10 1 0 1 0

Z=x|y 14 1 1 1 0

3. ^ - Bitwise XOR :-

The bitwise XOR compares the corresponding bits of its operand

and produces a 0 when both bits are 1 or both bits are 0.

Variable Decimal


X 12 1 1 0 0

Y 10 1 0 1 0

Z=x^y 6 0 1 1 0

4. << - Bitwise Shift Left :-

• The bitwise left shift operator takes a bit sequence as their

left operand and a positive integer n as their right operand.

• The output produces a left bit sequence but with shifted to

left side for n bit positions.

It can be initialized like :-

vaiable_name << Number of bit position

To perform (01 1010 0111 << 2 )

Variable Bit’s To Be Shifted Answer

00 1010 0111 2 1010 0111 00

5. >> - Bitwise Shift Right :-

• The bitwise right shift operator takes a bit sequence as their

left operand and a positive integer n as their right operand.

• The output produces a left bit sequence but with shifted to

right side for n bit positions.

It can be initialized like:-

vaiable_name >> Number of bit position



To perform (01 1010 0111 >> 2 )

Variable Bit’s To Be Shifted Answer

00 1010 0111 2 00 0010 1001

6. ~ - Bitwise Negation :-

• The bitwise negation operator is a unary operator that

complements the bits in its operand. Like 1 to 0 or 0 to 1.

xi ~xi

0 1

1 0



Question: Explain Enumerated Data Type in brief.

• An enumeration data type are data types whose variable can represent any

value that is from its already declared set of values.

• i.e. these are the data types whose value may be any member of

symbolically declared set of values.

• The enumeration data type are created to fix number of values that the

variable can have.

• For ex. We can declare a variable named days that can access only values

between (Sunday,Monday,Tuesday,….,Saturday);

• These symbolically declared members are basically an integer constants.

like 0,1,2,3,..

These symbolic integers are basically used to access any member values.+

THE GENERAL CONSTRUCT TO DECLARE A VARIABLE OF ENUMERATION

TYPE :

enum tag_name { member1, member2, … ,memberN } variable1,

variable2…..variablex;

Here In Above Declaration

1. tag_name : It is the name of variable used to access its members.

2. member1, member2…,memberN : These are the members or elements

for enumeration data type variable.

3. variable1, variable2,… , variablex : These are the variables of

enumeration data type.

• The enum tag_name defines the user-defined data type.

• All the members of enum variable can be accessed with integer constants.

By default , the first member , that is, member1 is given the value

0,member2 to value 1

• Members within the braces {} may be initialized, in which case, the next

member is given a value one more that the preceding member. So, each

member is given the value of the previous member plus 1.

The general form of declaring a variable of enum type is:

enum tag_name Variable1, Variable2,….., VariableN;

The variables can take the values which are its members like,

Variable1 = member1;



i.e. here the value represented by member1 is assigned to Variable1.

A typical declaration would be,

enum days { Mon , Tue, Wed, Thu, Fri, Sat, Sun };

void main()

{

enum days start, end;

start=Tue; //Means value of start=1;

end=Sat; //Means value of end=5

}

� Here the above declaration means that the values ‘Mon..Sat’ may be

assigned to a variable of type enum days.

� The above values are 0...6, in this example and these are values must be

associated with any input or output operations.



Question: What is Link List? Differentiate Array Vs. Link List. Explain

operations on Singly Linked List.

Definition: - A linked list is an ordered collection of elements, where each

element has at least one pointer for printing to the next element of the list

and at least one value.

Such an element is known as the node of a linked list.

Linked List Array

Memory Allocation :-

No overflow is possible.

� All memory offered for an

application available.

(I.e. at run-time, when new

storage is required.)

� The links need additional

space.

� (No any sequence is

maintained.)

Memory Allocation :-

� All memory must be allocation

before use. So, the memory

space allocated can be

exhausted or left unused.

� (Sequential memory

allocation.)

Accessing items :-

� Only sequential search is

possible.

Accessing items :-

� Random access is possible,

when the order (array index)

number is known.

Expressing order of items :-

� No order is maintain since

nodes may not be stored at

continuous memory

locations.

Expressing order of items :-

� The location in memory

indicates the order number of

item.

Efficiency of operation :-

� Insertion and deletion are

effective regardless (in any

case) of the position they are

inserted in.

Efficiency of operation :-

� Many data movements are

needed in insertions and in

deletion of items.(because of

sequential memory

allocation)

Programming :-

� Needs a bit of expertise.

Programming :-

� Very easy.

� What is meant for singly linked list?

Definition:- A singly linked list is simply a sequence of dynamically allocated

objects, each of which refers to its successor in the list.

� All the operations on Singly Linked List.

� Insert a node :-

Insertion is further classified into three different parts.



• After a particular node

(Insert after particular (given/specified) node.)

• After nth node

(Insert at the last position in the list.)

• Before a particular node

(Insert before particular node.)

� Search a particular node

� Remove a particular node

� Sort the nodes

� Destroy (delete all nodes)



Question: Define Structure. What are the difference between Structure

and Union? Explain the concept of Nested Structure with example.

� Structure is a user-defined data type may also be called a derived

data type.

� It can be work with collection of data as separate variables.

� Nesting structure is also possible.

Structure Union

� Every member has its

own memory.

� The keyword used is

struct.

� All members occupy

separate memory

locations; hence different

interpretations of the

same memory location

are not possible.

� Consume (use) more

space compared to union.

� All the members can be

initialized.

� Use sizeof keyword in

structure it returns size

of all the members.

� All members use the same

memory.

� The keyword used is union.

� Different interpretations for the

same memory location are

possible. (memory is shared by

all the members)

� Conservation (saving) of

memory is possible.

� Only first member can be

initialized.

� Use sizeof keyword in union it

returns size of biggest member

in the union.

� Nested structure :-

Definition:- A structure can be placed within another structure. In other

words, structures can contain other structures as member.

� A structure within a structure means nesting of structures.

� In such a case, the dot operators in conjunction with the structure

variables are used to access the members of the innermost as well

as outermost structures.



� An example of nesting of structure:-

struct Date

{

int dd, mm, yy;

};

struct Student

{

int rno;

char name[15];

struct Date b_date; //Declaration of structure within structure (Nested)

};

void main()

{

struct Student s1;

// Initialize members of structure

s1.rno = 1;

strcpy(s1.name, "Haresh");

/* Initialize member of nested structure Date */

s1.b_date.dd = 12;

s1.b_date.mm = 4;

s1.b_date.yy = 1989;

// Print members of structure

printf("\nRoll No.: %d", s1.rno);

printf("\nName : %s", s1.name);

/* To print members of nested structure Date */

printf("\nB_Date : %d-%d-%d", s1.b_date.dd, s1.b_date.mm,

s1.b_date.yy);

getch();

}



Question: Explain following concept with example

(1) RECURSIVE FUNCTION AND ITS APPLICATION

(2) COMMAND LINE ARGUMENTS

(1) RECURSIVE FUNCTION AND ITS APPLICATION:

Basic Concept of recursion or comparison with looping (JUST FOR

UNDERSTANDING):

1) As we all know that loop (for, while, do..while) is used to execute the code

again and again.

2) We require a condition that stop the execution of loop and execute the next

instruction.

3) For example,

We are going to add first 5 natural no. using for loop basic syntax

would be something like ….

For (i=1;i<=5;i++)

{

Total = Total + i;

}

Let us assume that initially Variable Total is assigned the value 0 first instruction

will add the value 1 to variable total now the value of variable total is 1 .

Next instruction will add value of variable i to total. Now, the value of total is 3

and so on the value of variable i will be added to total until the condition is

satisfy.

Same way as the looping work the recursive function works.

As we require a termination condition in for loop same way we required a

termination condition for the recursive function also.

Let us see an example,

int addno(int n) {

if(n<5)

{

return ( n + addno(n+1));



}

}

In the above example will add the first 5 value n. The value of n will be increment

by one (1) every time function calls and terminate the recursive call when the

value of n is greater than 5.

Definition:

A recursive function is one that calls itself directly or indirectly to solve a

smaller version of its task until a final call which does not require a self-

call. OR

A function that calls itself is called the recursive function.

Characteristics of recursion

1) Recursion function requires stopping at any certain condition.

Otherwise, the recursion process will be infinite.

2) Recursion function prepares the stack every time function calls.

Stack would be something like:

Example

Let us see an example of factorial no using recursion …

#include<stdio.h>

long int factorial(int number) /* function prototype */

void main()

{

int i;

printf(“\n Enter the number:”);

scanf(“%d”,&i);

printf(“\n Factorial no:%d”,factorial(i));



getch();

}

long int factorial(int number)

{

If(number<0)

{

printf(“\nError- negative argument to factorial”);

exit(1);

}

else if(number==0)

{

return 1;

}

else

{

return (number * factorial(number-1));

}

}

Application of recursion function

1) Recursion function used in constructing graph

2) Recursion function used for the tree like structure also.

For e.g. In our day to day like life we are see many type of MLM Company

Means first you become member and make sub-member under yourself

that type of problem to convert into (technical) we must have to use the

recursion process. Basically this is a tree like structure.

M1

M2 M3 M4

M5 M6 M7



(2) COMMAND LINE ARGUMENT:

Why use command line argument?

We are using array in c programming language such like int arr[10]

And allocating value of to array of 10 in an array. The main drawback of the

using array is

1) if we use five array index or assign five value to the given array then the

rest of five element will be unused.

2) We can’t assign more than 10 values to an array of such type.

The command line argument overcome such kind of disadvantages

Basic syntax:

int main(int argc, char *argv[])

The declaration states that :

1) main returns an integer value (used to determine if the program

terminates successfully).

2) argc stands for argument counter and it counts the number of

argument passed by the user argc must be at least 1.

3) argv stands for Argument vector is an array of character type which

hold the argument passed by the user.

Let us see an example of finding max value using command line argument:

#include<stdio.h>

void main(int argc, char *argv[])

{

int I=1,max;

max=atoi(argv[1]);

for(i=1;i<argc;i++)

{



If(max<atoi(argv[i]))

{

max = atoi(argv[i]);

}

}

printf(“Max value is:%d”,max);

getch();

}

The above program must be execute using DOS prompt

First argument must be name of the file and rest of the argument will be

NUMBER because we are finding maximum value from an argument.

The atoi function will convert character type to int type. We need to use

this function to convert character argument into int type.



Question: What is Preprocessor? Explain it in brief.

� The C preprocessor is used to modify the program according to the

preprocessor directives in the source code.

� A preprocessor directive is statement that gives the preprocessor specific

instructions on how to modify the source code.

� The preprocessor is invoked as the first step of the compilation process.

� It is usually hidden from the programmer because the compiler runs it

automatically.

� It is advantageous to use the preprocessor because it Makes:-

1. Program development easier.

2. Programs easier to read.

3. Modification of programs easier.

4. C code more transportable between different machine architectures.

The Bellow display the preprocessor Directives:-



UNCONDITIONAL:-

(1) #define:-

� The #define causes the compiler to go through the program,replacing

every occurrence of macro_name with replacement_string.

� The replacement string stops at the end of the line. No semicolon is used at

the end of the directive.

� The general form for the define directive is

#define marco_name replacement_string

For Example:

#define print printf

void main()

{

print(“Welcom to C world”);

}

(2) #undef:-

� This directive undefines a macro.

� A macro must be undefined before being redefined to a dirrerent value.

� The use of #undef on an undefined identifier is harmless and has no effect.

� #undef takes a single argument, the name of the macro to be undefined.

� The general form of #undef directive is

#undef marcor_name

For example:

#undef print

(3) #include:-

� The first form is used for referring to the standard system header files.

� It searches for a file named file_name in a standard header file library and

insert it at the current location.

� They must be included before the program can make use of the library

function.



� The angle brackets,< > indicates the preprocessor to search for the header

file in the standard location for library definitions.

� The second from searches for a file in the current directory.

� This is used where multi file programs are being written ,Certain

information is required at the beginning of each program file.

� it is conventional to gives header files a name that ends in ‘.h’ to

distinguish them from other types of files.

� The general directgive has two general froms

#include <file name>

and

#include “file name”

For example:-

#include<stdio.h>

void main()

{

printf(“Welcome again the c World”);

}

� The C have by default it can provided the stdio.h header file.

(4) #Line:-

� The #line directive is used to change the value of __LINE__ and __FILE__

variable.

� The file name is optional.

� The __FILE__ and the __LINE__ variable represent the current file and line

that is being read.

The general form of the directive:-

#line line_number <file name>

For example:-

#line 20 “program1.c”

� The above example to change the current line number to 20,and current

file to “program1.c”.\



(5) #error:-

� The preprocessor #error is used for reporting errors by the preprocessor.

� The general from is

#error error_message

� When the preprocessor encounters this, it output the error_message and

causes the compilation to be aborted.

� Therefore it should be only used for reporting errors that make further

compilation pointless or impossible.

For Example:-

#ifdef LINUX

#error This software requires the LINUX OS.

#endif

(6) #pragma:-

� The #pragma directive allows the programmer the ability to convey to the

compiler to do certain tasks.

� Since the #pragma directive is implementation-specific, uses vary from

compiler to compiler.

CONDITIONAL:-

(1) #if (2) #elfi (3) #else (4) #endif :

� Here #if is a conditional directive of the preprocessor, it has expression

that evaluates to an integer.

� #elif is same as the else_if ladder of c,and else is also used with #if or #elif

directive is required. And #endif is used to delimit the end of statement or

condition.

� Above all the conditional preprocessor is also same as work of the if,else_if

and the endif of constructed of C.

� The general format of this condtional preprocessor is:-

#if <constant_expressions1>

<statement_sequencel1>

#elif <constant_expression2>

<statement_sequences2>



#elif<constant_ expression3>

<statement_sequences3>

#else

<statement_sequences>

#endif

For Example:-

#If SYSTEM1.H

#include “system_1.h”

#elif SYSTEM2.H


#else


#endif

(5) #ifdef (6) #ifndef:-

� The #ifdef directive executes a statement sequences if the macro_name is

defined.

� if the macro_name is not defined, the #ifndef directive executes a

statement sequences, for both the directives, the end of statement is

delimited by #endif.

� The general form of

#ifdef :- #ifdef macro_name

<statement_sequences>

#endif

#ifndef :- #ifndef macro_name

<statement_exrpression>

#endif



Question: Scope and Life time of Variable in C ?

� The period of time during which memory is associated with the identifier

is extent, of the variable, the region of the program over which the

declaration of an identifier is visible is called the scope and identifier.

� The scope relates to the accessibility the period of existence and the

boundary of usage of variables declared in a statement block or a function.

� These features in turn define whether a variable is local or global in

nature.

� The variables declared in a block are accessible and usable within that

block ({}).it means this type of variable is life is only between { }.

� We can define the global variable that mean define the variable global

declaration or above the main () is called global variable In this type of

variable life is whole program.

� The bellow display the scope and life time of variable

void main()

{

int x=3;

printf(“The Outer block:=%d”,x);

{

int x=45;

printf(“The inner block=>%d”,x);

}

printf(“Outer block:=%d”,x);

}

Output:-

The Outer Block=3

The Inner Block=45

The Outer Block=3

Start Outer Block

End of Outer Block

Start Inner Block

End of Inner Block



� The above program show that because the variable x has been redeclared

as 45 in the inner block,a local variable gets created in the inner block,this

variable is only accessible and known as the inner block.



Question: Explain if and nested if. What is different between nested if and

ternary operator?

o IF

• If statement is known as one way decision handler.

• One way decisions are handled with if statement that either do

something or do nothing at all.

• That decision is depend on “test Expression”.

• That general form is following.

if (test expression)

{

Statement-1;

……….

Statement-n;

}

Figure illustration:

true false

• In the above, figure Test Express is logical condition either it is true or

false

Test Expres

Statement_n

STOP



• If the condition is true then the statement available in the if block are

executed.

• Otherwise next operation is executed or program is terminated.

int a=10, b=20;

if (a<b)

{

printf (“A is MINIMUM”);

}

• In the above example, if A is smaller than the B then the “A is

MINIMUM” print on the screen.

• Otherwise program stop that execution.

o Nested if:

• A nested if is an if that is the target of another if or else

• In a nested if, an else statement always refers to the nearest if

statement that is within the same block as the else and that is not

already associated with an else

• The general form of nested…if is following:

if (logical condition)

{

if (logical condition)

{

Outer condition

Inner condition



Statements;

}

else

{

Statements;

}

Statements;

}

• If the outer condition is true then after the inner condition execute.

int a=30,b=20,c=40;

if (a>b)

{

if (a>c)

{

printf("A is MAX");

}

else

{

printf("C is MAX");

}

}

else

{

Inner else



if(b>c)

{

printf("B is MAX");

}

else

{

printf("C is MAX");

}

}

Different between nested…if and ternary operator

• Nested…if: it one type of technique to selecting true or false execution.

• In that, there is outer block or inner block.

• Ternary Operator: Three operand are used in operation that is

known as ternary operator.

• The main difference between the Nested…if and Ternary Operator

is FLEXIBILITY

� In the Nested if, we must write block wise so that code may

be long.

� Long cannot provides the flexibility because of debugging

or error correction are difficult.

� EX. Show the example of 2.0

� In the other hand, there are only required one statement

to produces the code of example 2.0

� Shown below:



int a=60,b=50,c=40;

a>b ?

( a>c ? printf("A is MAX"):printf("C is MAX") ) :

(b>c ? printf ("B is MAX"):printf("C is MAX") );

• In the nested if, there are use two keyword IF and ELSE.

• Other hand in the ternary operator, there are used two operator? and :

• The main advantage of the nested if is two return type can be

different in the if or else part.

• While in the ternary operator return type are same.



Question: Explain the Process of Completion. Differentiate Compiler Vs.

Interpreter

Answer: Compiling process consists of two steps:

1) The analysis of the source program.

2) The synthesis of the program in the machine language .

� The analysis phase uses the precise description of the source

programming language.

� A source language is described using lexical rules, syntax rules and

semantic rules.

Fig-(The process compiler)

� Lexical rules specify the valid syntactic element of language.

� Syntax rules specify the way in which syntactic elements are

combination to form the statements of the language.

� Lexical analyzer:- It take successive line of a program and breaks

them into individual lexical item namely, identifier, Operator

delimiter,etc.



� And attaches with a symbol table for each identifier and find internal

repetition of each constant.

� The symbol table is used later to allocate memory to each variable.

� Syntax analysis:- It is use expression, declaration, and other

statement are identified by using the result of lexical analysis.

� Semantic analysis:- In this, the syntactic units recognized by the

syntax analyzer are processed.

� An intermediate representation of the final machine language code is

produced.

� The last, code translation is code generation, when optimization to

reduce the length of machine language program is carried out.

� The out of the code generator is a machine level language program for

the specific computer.

� The execution of a program written in high-level language involves the

following steps:

1. Translation

2. Linking

3. Relocation

4. loading

Linker:-

� Linker resolves symbolic references between object program.

� Features of programming language influence the linking requirement of

a program.

� Linking is used in many languages like FORTRAN/COBOL, for give the

reference of variable.

� In c files are transfer separately, so function calls with the reference to

global data require linking.

Relocation:-

� Relocation means abjection of all address dependant locations, such as

address constant, to correspond to the allocation space.

� Relocation is used moving program to one area to another area.

Loader:-

� Loading means physically placing the instructions and data into main

memory.



� A loader is a system program that accept object program and prepares

them for execution and initiates.

Function of loader:-

� Assignment of load-time storage area to the program.

� Loading of program into assigned area.

� Relocation of program to execute properly from its load

time storage area.

� Linking of programs with one another.

Difference between a compiler and an Interpreter

COMPILER INTERPRETER

Scans the entire program before

translating it into machine code.

Translates and executes the program

line by line.

Converts the entire program to

machine code and only when all the

syntax errors Removed do execution

take place.

Each time the program is executed;

every line is checked for syntax error

and then converted into the equivalent

machine code.

Slow in debugging. Good for fast debugging.

Execution time is less. Execution time is more.



Question: Explain Ternary (Conditional) Operator in Brief.

• The conditional operator ternary operator has three expressions. It has the

general form

expression1 ? expression2 : expression3

• First, expression1 is evaluated; it is treated as a logical condition. If the

result is non-zero, then expression2 is evaluated and its value is the final

results. Otherwise, expression3 is evaluated and its value is the final result.

For example:

int M=1,N=2,Min;

Min = ( M<N ? M : N ); //Min is assigned a value 1

• In the above example,because M is less than N,M<N expression evaluates

to true,therefore,Min is assigned the value M,i.e.,1.

• The same code can also be written using the if-else construct

int M=1,N=2,Min;

if(M<N)

{

Min=M;

}

else

{

Min=N;

}

• Note that out of the second and the third expressions of the conditional

operator, only one is evaluated. This may be significant when one or both

contain side effects, that is, their evaluation causes a change to the value of

a variable.

For example, in

Min= (M<N ? M++ : N++ );



• M is incremented because M is less than N and N is not incremented and

not changed.

• Because a conditional operation is itself an expression,it may be used as an

operand of another conditional operation,that is,expression may be

nested.

int M=1,N=2,P=3,Min;

Min=(M<N?(M<P?M:P):(N<P?N:P));

• First of all M<N condition is checked if it is evaluated to true then M<P

condition is checked if it is evaluated true then M is printed otherwise N is

printed.

• If M<N condition is evaluated to false then N<P condition is checked if it is

evaluated to true the N is printed otherwise P is printed.

• The conditional expression is not only a shorthand; It may also result in

less object code than would be generated by other alternative means, e.g.,

by use of one or more if statements.



Question: Explain different File Opening Modes used with fopen ().

What is fopen () :-

• fopen() is used for opening a file.

• The fopen ( ) function opens a stream for use and links a file with that stream.

• Then it returns the file pointer associated with that file.

• Syntes :-

• FILE *fopen(const char *filename, const char *mode);

• Example:-

FILE *fp;

fp = fopen("test", "w");

The modes used with fopen() :-

Modes Meaning

R Open a text file for reading

W Create a text file for writing

A Append to a text file

Rb Open a binary file for reading

wb Create a binary file for writing

ab Append to a binary file

r+ Open a text file for read/write

w+ Create a text file for read/write

a+ Append or create a text file for read/write

r+b Open a binary file for read/write

w+b Create a binary file for read/write

a+b Append or create a binary file for read/write



Question: Write a short note on Type of Stream in C.

What is Stream:-

“The Stream is a common, logical interface to the various devices that

comprise the computer.”

Stream:-

• A very important concept in C is the stream.

• In its most common form, a stream is a logical interface to a file.

• As defined by C, the term ‘file’ can refer to a disk file, the screen, the

keyboard, a port, a file on tape, and so on.

• Although files differ in form and capabilities, all streams are the same.

• The Stream provides a consistent interface to the programmer.

• Stream I/O uses some temporary storage area, called buffer, for reading

from or writing data to a file.

• This is illustrated in following figure.

• The C file system is designed to work with a wide variety of devices,

including terminals, disk drives, and tape drives.

• Even though each device is very different, the buffered file system

transforms each into a logical device called a stream. All streams behave

similarly.



• Because streams are largely device independent, the same function that

can write to a disk file can also write to another type of device, such as the

console.

• There are two types of streams: text and binary.

Text Streams:-

• A Text stream is a sequence of characters.

• Standard C states that a text stream is organized into lines terminated by a

newline character.

• However, the newline character is optional on the last line.

• In a text stream, certain character translations may occur as required by

the host environment.

• For example, a newline may be converted to a carriage return/linefeed

pair.

• Therefore, there may not be a one-to-one relationship between the

characters that are written (or read) and those stored on the external

device.

• Also, because of possible translations, the number of characters written

(or read) may not be the same as the number that is stored on the external

device.

Binary Streams:-

• A Binary stream is a sequence of bytes that has a one-to-one

correspondence to the bytes in the external device— that is, no character

translations occur.

• Also, the number of bytes written (or read) is the same as the number on

the external device.

• However, an implementation— defined number of null bytes may be

appended to a binary stream.

• These null bytes might be used to pad the information so that it fills a

sector on a disk.



Question: Explain concept of (1) Array of Pointer (2) Pointer to Array

(1) Array of Pointer:

• Pointers and Arrays are logically related, but they are not same.

• Array of pointer is a collection of Pointers.

• In general, an array of pointers can be used to point to an array of data

items, with each element of pointer array pointing to an element of the

data array.

• The advantage of an array of pointers is that the pointers can be reordered

in any manner without moving the data items. Because reordering

pointers is relatively fast compared to recording large data items such as

data records or strings.

Declaration Syntax of Array of Pointer:

data_type array_name[SIZE];

Note: - SIZE represents the number of rows.

• An array of pointers can be declared very easily. Like as,

int *p[10];

• This declares an array of 10 pointers, each of which points to an integer.

• The first pointer is called p[0], the second is p[1], and so on up to p[9].

• We could make point to integer variable in memory.

For Example:

int *p[10]; int a=10,b=20,c=30;

p[0] = &a; p[1] = &b; p[2] = &c;

• • •

10 20 30



• It can be seen from the diagram that the first pointer p[0] is points to a, the

second pointer is point to b, and so on up to p[9].

• Access value of pointer of array in 1-Dimension array.

printf(“%d”,*p[2]); //get value 30

• But in 2 dimension array assignment of pointer and accessing pointer

value is different.

Assignment pointer in 2-Dimension:

int a[3][3]={{1,2,3},{4,5,6},{7,8,9}}

int *p[3],i,j;

for(i=0;i<3;i++)

{

p[i]=&a[i][0];

}

Accessing value of pointer in 2-Dimension:

for(i=0;i<3;i++)

{

for(j=0;j<3;j++)

{

printf(“%3d”,*(*(p+i)+j));

}

}

1 2 3

4 5 6

7 8 9

Output

1 2 3

4 5 6

7 8 9

p[0]

p[1]

p[2]



(2) Pointers to an Array :

• Suppose we have an array of integer data type, which name is v. We can

declare integer value and make it point to the array as is done normally.

int v[5] = {10,11,12,13};

int *p ; p=&v;

printf(“%d \n”,*p);

V[0]

V[1]

V[2]

V[3]

V[4]

• Using p++, increases the pointer so that it points to the next element of

the array. Now p is point to the v[1].

• Similarly, we can use instructions such as += and -= to refer to different

elements in the array.

V[0]

V[1]

V[2]

V[3]

V[4]

10

11

12

13

14

10

11

12

13

14

p

p

p+=2;



V[0]

V[1]

V[2]

V[3]

V[4]

• Reference can be made to the different array element without having to

after the value of p.

V[0]

V[1]

V[2]

V[3]

V[4]

• We have already used *p to refer to the first element of the array, but

*(p+1) refer to the next element after *p, *(p+2) to refer to the one after

that, etc.

• Now it is time to the problem of the two-dimension array. The first

element of a 2-D array of integers is a one-dimensional array of integer.

And a pointer to a 2-D array of integers must be a pointer to that data

type.

• One way of declaring a pointer in 2-D without typedef keyword, it is

pointer to array.

Declaration Syntax of Pointer to an Array:

data_type (*array_name)[SIZE];

SIZE represents the number of columns.

10

11

12

13

14

10

11

12

13

14

p

p--;

*p

*(p-1)

*(p+1)

*(p+2)

*(p+3)



Assign value in Pointer in 2-D:

int a[2][3]={{3,4,5},{6,7,8}};

int (*pa)[3];

pa =&a[0];

Accessing value From 2-D using Pointer to Array:

for(i=0;i<2;i++)

{

for(j=0;j<3;j++)

{

printf("%d\t",(*(pa+i))[j]);

}

printf("\n");

}

Output :

3 4 5

6 7 8



Question: Explain Escape Sequence:

• Character combinations consisting of a backslash (\) followed by a letter

or by a combination of digits is called "escape sequences”.

• C language supports some special character constants that are used in

output functions.

Example:

The symbol ‘\n’ stands for newline characters.

Backslash Character Constants:

Constant Meaning

‘\n’ New line

‘\t’ Horizontal tab

‘\v’ Vertical tab

‘\?’ Question mark

‘\\’ Backslash

‘\0’ Null

‘\a’ Audible alert

‘\b’ Back space

‘\f’ Form feed

‘\’’ Single quote

‘\’’’ Double quote

‘\r’ Carriage return

• List of above backslash character constants table that each one of them

represents one character, all though they consist of two characters. These

characters combination are known as “escape sequences”.

• Give one example for each.



Question: Explain Formatted I/O Statements in C.

• In C language formatted I/O statements is required in a specified format

the two standard library function that are the under

1. printf()

2. Scanf()

(1) Input function printf():

• The printf() function useful for printing captions and numerical results. It

is highly desirable that the outputs are produced in such a way that are

understandable and are in an easy-to-use form

• The general form of printf statements is under :

Syntax:

printf(“control string “,arg1,arg2,…..,argn);

(a) Control String:

• Control string consists of three types of items

1. Character that will be printed on the screen as they appear.

2. Format specifications that define the output format for display of each

item, The output format specifier are preceded by a % sign and tell

printf( ) what type of data is to be print, Format specifiers for printf()

are under.

Conv.

code

variable type Display

%c char Single character

%d(%i) int Singed integer

%E(%e) float or double Exponential format

%f float or double Signed decimal

%g(%G) float or double Use %f or %e, whichever is sorter

%o int Unsigned octal value

%p pointer Address stored in pointer

%s Array of char Sequence of characters

%u int Unsigned decimal integer

%x(%X) int Unsigned hex value

%% None No corresponding argument is converted,

prints only a %

%n Pointer to int The corresponding arguments is a pointer to

an integer into which the number of character

displayed is placed



3. Escape sequence character

Such as: \n,\t,\b…etc

(b) Arguments:

• The arguments arg1,arg2,arg3…argn are the variables whose values are

formatted and printed according to the specification of the control string.

(2) Input function scanf():

• scanf( ) is the general -purpose console input routine. It can read all the

built-in data types and automatically convert numbers into the proper

internal format. It is much like the reverse of printf( ).

• The general form of scanf() statements is under :

Syntax:

scanf(“control string“,variable1_address, ,…..,variableN_address);

• The scanf( ) function returns the number of data items successfully

assigned a value. If an erroroccurs, scanf( ) returns EOF. The

control_string determines how values are read into the variables pointed

to in the argument list.

• The control string consists of three classifications of characters:

(1) Format specifier:

• Format specifications that define the get format for display of

each item for printf(), The input format specifier are preceded by

a % sign and tell scanf( ) The format specifier are matched, in

order from left to right.

Conversion

code

Meaning

%c Read Single character

%d(%i) Read s Singed integer

%E(%e) Read floating point number

%f Read a floating point number

%g(%G) Read a floating point number

%o Read octal number

%p Read a pointer

%s Read a string

%u Read an Unsigned decimal integer



%x(%X) Read a Unsigned hex value

%% Read a percent sign

%[] Scans for a set of characters.

%n Receives an integer value equal to

the number of characters read.

• White-space characters

• Non-white-space characters

(2)Variable address

• The variable_address1, variable_address2,…, variable_addressN

that pass the address of the variable using the ‘&’ operator.

Example:

#include <stdio.h>

void main()

{

int i, j;

printf(“enter value of I and J “);

scanf("%o%x", &i, &j);

printf(''%o %x", i, j);

getch();

}



Differences

Break Continue

It helps to make an earlier exit from the

Block where it appears.

It can be used in all control statements

Including switch construct.

Control passes to the next statement.

It breaks the loop.

It helps in avoiding the remaining

statements in a current iteration

It can be used only in loop constructs.

Control passes at the beginning of the loop

It does not break the loop.

Call/ Pass by Value Call / Pass by Reference

• Pass by value return the value to

the main function

• Pass by reference return the address

to the main function.

• Change in the subfunction does

not reflect to the main function

• Change in the subfunction reflects to

the main function.

• It can return only one value of

variable.

• It can return more than one value of

variables because it return reference

• In Function call value is passed. • In Function call address is passed.

• C and Java restrict themselves to

Call by Value.

• C++ and Pascal let you declare that a

parameter is a reference.

• Value of actual parameter is used

to initialize the formal

parameter.

• Formal parameter refers to the same

memory cell for the actual

parameter.

do…while while

while is entry control loop

First it executes body of the loop then

it will check the condition.

If condition is false although body loop

will execute one time.

It will execute one more time then while

loop.

Do while is exit control loop

First it checks the condition then execute

body of the loop

If condition will be false then it will came

out of the loop.

It will execute one time less the do while

loop.



Explain Operator precedence and operator Associativity in brief.

Operator precedence:

� When more than one operator are present in an expression, operator

precedence decides which operator is evaluate first.

� Operator precedence is known as operator priority

Operator Associativity:

� When more than one operator with same precedence are present

,operator associativity operator is evaluated left to right or visa versa

Table Operator precedence And operator Associativity

operator Associativity precedence

( ) [] -> . ++(postfix) --(postfix) L to R 1

++(prefix) --(prefix) ! ~ (1’s compli.) sizeof(type)

+(unary)

-(unary) &(address) * (pointer reference)

R to L

2

* / % L to R 3

+ - L to R 4

<< >> L to R 5

< <= > >= L to R 6

== != L to R 7

& L to R 8

^ L to R 9

| L to R 10

&& L to R 11



Example of precedence of operator

void main()

{

int a;

int b=4;

int c=8;

int d=2;

int e=4;

int f=2;

a=b + c / d + e * f; /* =4+8/2+4*2 =4+4+4*2 =4+4+8 =16 */

printf(“\n a=%d”,a);

a=( b +c ) / d + e * f ; /*=(4+8)/2+4*2 =12/2+4*2 = 6+8 =14 */

printf(“\na=%d”,a);

}

Output

a=16

a=14

|| L to R 12

? : R to L 13

= += -= *= /= %= >>= <<= &= ^= |= R to L 14

,(comma operator) L to R 15



Question: What is ALGORITHM? Explain feature of it. List different way of

stating algorithm.

• An algorithm is an “effective” procedure for solving a problem in a finite

number of steps.

THE KEY FEATURES OF ALGORITHM:-

There are three key features of an algorithm.

(1) Sequence (also known as process)

(2) Decision. (also known as selection)

(3) Repetition (also known as iteration or looping)

(1) Sequence:-

• Sequence means that each steps or process in the algorithm is expressed in

the specified order, otherwise, it will fail.

(2) Decision:-

• In algorithm the outcomes of a decision is either true or false; there is no

state in between.

• The decision can also be stated as:

If proposition

Then proceses1

else

Process2

(3) Repetition:-

• Repetition can be implemented using construct like the repeat loop,

while loop, and if..then…goto..loop.

• The repeat loop is used to iterate or repeat a process or sequence of

processes until some condition becomes true.

• It has general form



REPEATE

PROCESS1

PROCESS2

…

…

PROCESSN

until proposition.

• The repeated loop does some processing before testing the state of the

proposition.

DIFFERENT TYPES OF STATING ALGORITHM:-

(1) Step –form

(2) Pseudo-code

(3) Flowchart

(4) Nassi-Schneiderman



Question: What is Flowchart? Explain in brief.

Flowchart:-

• It is a program designed tool which is used before writing the actual

program.

• Flowcharts are generally developed in the early stages of formulating

computer solution.

Symbols Used in Flowchart:-



Advantage of Using Flowchart:-

• Communication:-

Flow charts are a better ways of communicating the logic of a

system to all concerned.

• Effective Analysis:-

With the help of flow charts, problems can be analyzed more

effectively.

• Proper Documentation:-

Program flowcharts harts serve as a good program documentation

needed for various purposes.

• Effective Coding:-

Flowcharts acts as a guide or blueprint during the systems analysis

and program development phase.

• Proper debugging:-

Flowcharts help in the debugging process.

• Effective program maintenance:-

The maintenance of an operating program becomes easy with the

help of a flowchart.

Limitations of using flowchart:-

• Complex logic sometimes, the program logic is quit complicated. In

such a case, a flowchart becomes complex and clumsy.

• Alternation and modifications if alteration are required, the flowchart

may need to be redrawn completely.

• Reproduction Since the flowchart symbols cannot be typed in, the

reproduction of a flowchart becomes a problem.

• The essentials of what has to be done can easily be lost into the

technical details of how it is to be done.

Documents

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