Operators-computer programming and utilzation

COMPUTER PROGRAMING AND UTILIZATION

By Kaushal Patel

TYPES OF OPERATORS

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Operators are the verbs of a language that help the user perform computations on values.

“An operator is a symbol (+,-,*,/) that directs the computer to perform certain mathematical or logical manipulations and is usually used to manipulate data and variables”Ex: a + b

Definition

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Operators in C

1. Arithmetic operators2. Relational operators3. Logical operators4. Assignment operators5. Increment and decrement operators6. Conditional operators7. Bitwise operators8. Special operators

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Arithmetic operators

Arithmetic operators are used to perform arithmetic operations. ‘C’ language supports following arithmetic operators.

Operator example Meaning

+ a + b Addition –unary

- a – b Subtraction- unary

* a * b Multiplication

/ a / b Division

% a % b Modulo division- remainder

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The ‘C’ language does not provide the operator for exponentiation. + and – operator can be used as unary operator also. Except % operator all arithmetic can be used with any type of numeric operands, while % operator can only be used with integer data type only.

Following program will clarify how arithmetic operators behave with different data type, particularly the use of /and % operator.

Arithmetic operators

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Example:-# include<stdio.h> main(){ int x=25; int y=4; printf(“%d+%d=%d\n” ,x, y, x+y); printf(“%d-%d=%d\n” ,x, y, x-y); printf(“%d*%d=%d\n” ,x, y, x*y); printf(“%d/%d=%d\n” ,x, y, x/y); printf(“%d%%d=%d\n” ,x, y, x%y);}

Arithmetic operators

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Output:-25+4 =2925-4=2125*4=10025/4=625%4=1

Arithmetic operators

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Explanation: First three operations are obvious. The division operation gives the answer 6 because, the variables x and y are integer variables, when we use / with integer operands the result will be integer number. while,%operator produce the remainder after division of 25by 4.

Arithmetic operators

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Assignment Operators

We have already used the assignment operator = in previous programs ‘C’ language supports = assignment operator. It is used to assign a value to a variable. The syntax is

variablename = expressionThe expression can be a constant, variable name or any

valid expression. ‘C’ also supports the use of shorthand notation also. form is variable = varname operator expression; into varname operator = expression;

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Assignment Operators

Use of shorthand notation makes your statement concise and program writing becomes faster when variable name are long in size

Assignment Operator Shorthand

a = a + 5; a += 5;

a = a – 5; a -= 5;

a = a * 5; a *= 5;

a = a /5; a /= 5;

a = a % 5(assuming a as integer) a %= 5;

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Assignment Operators

Example:- #include<stdio.h>#include<conio.h> void main(){

int a;clrscr();printf(“Give the value of a\n”);scanf(“%d”,&a);a += 5;printf(“a= %d\n”,a);a -= 5;printf (“a =%d\n”,a);getch();

}

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Assignment Operators

Output:-Give the value of a4a =9a =4

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Logical Operators

Sometimes in programming, we need to take certain action if some condition are true or false. Logical operators help us to combine more than one conditions, and based on the outcome certain steps are taken.

Operator name Meaning

&& Logical AND

|| Logical OR

! Logical NOT(Negation)

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Logical Operators

Logical NOT is an unary operator. In an expression, we can use more then on logical operation. If more then one operator is used, !(NOT) is evaluated first, then &&(AND) and then ||(OR), we can use parentheses to change the order of evaluation.

for example, if we have a = 2, b = 3 and c = 5 then,Expression Value Remark

a <b && c ==5 True Both expression are true

! (5 >3) False 5>3 is true & negation of true is false

a< b || c=10 True a<b is true which makes the expression true

(b> a) && (c !=5) False c =5, s0 second condition false

(b<c || b>a) && (c==5)

True Both sub expression are true

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Increment & Decrement Operators

C supports 2 useful operators namely1. Increment (++)2. Decrement(--)operatorsThe (++) operator adds a value 1 to the

operandThe (--) operator subtracts 1 from the operand (++a) or (a++) (--a) or (a--)

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Examples for (++) &(--) operators:-

Let the value of a =5 and b=++a thena = b =6Let the value of a = 5 and b=a++ thena =5 but b=6i.e.: 1. a prefix operator first adds 1 to the operand and

then the result is assigned to the variable on the left

ex:- (++a)or (--a) is called prefix increment or decrement

2. a postfix operator first assigns the value to the variable on left and then increments the operand.

ex:- (a++)or (a--) is called postfix increment or decrement

Increment & Decrement Operators

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If the ++ or – operator is used in an expression or assignment then prefix notation give different values. Ones should use prefix notation carefully in an assignment or expression involving other variables.

Increment & Decrement Operators

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Example:-#include <stdio.h>#include <conio.h>main(){ int x=10; int y; int z=0; clrscr(); x++; ++x; y=++x; printf(“ Value of x=%d y=%d and z-%d\n”, x,y,z); z=y--; printf(“ Value of x=%d y=%d and z-%d\n”, x,y,z);}

Increment & Decrement Operators

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Output:-Value of x=13 y=13 and z=0Value of x=13 y=12 and z=13

Increment & Decrement Operators

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C language has two useful operators called increment(++) and decrement

(--) that operate on integer data only. The increment (++) operator increments the operand by

1, while the decrement operator (--) decrements the operand by 1, for example ,:

int i , j;i = 10;

j = i++ ; printf(“ %d %d “, i, j);OUTPUT:-

11 10 . First i is assigned to j and then i is incremented by 1

Increment & Decrement Operators

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If we have : int i, j ;

I = 20;j = ++i;printf(“%d %d”, i, j);

OUTPUT : first i is incremented by 1 and then assignment take

place i.e., pre- increment of i. now, consider the example for (--) operator :

int a, b;a=10;b= a--;printf(“%d %d”, a , b)

OUTPUT : first a is assigned to b then a is decremented by 1.

i.e.,post decrement takes place

Increment & Decrement Operators

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Decrement Operator:-

If we have : int i, j ;I = 20;j = --i;printf(“%d %d”, i, j);

OUTPUT : 19 19. first i is decremented by 1 and then assignment take place i.e., pre-decrement of i.

Note : on some compilers a space is required on both sides of ++I or i++ , i-- or --i

Increment & Decrement Operators

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Bitwise Operators

We know that internally, the data is represented in bits 0 and 1. ‘C’ language supports some operators which can perform at the bit level. These type of operations are normally done in assembly or machine level programming. But, ‘C’ language supports bit level manipulation also, that is why ‘C’ language is also known as middle-level programming language.

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Bitwise Operators

Following table shows bit-wise operators with their meaning:

Operator name Meaning

& Bit-wise AND

| Bit-wise OR

^ Bit-wise Exclusive OR(XOR)

<< Left Shift

>> Right Shift

- Bit-wise 1’s component

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Bitwise Operators

Examples:-#include<stdio.h>#include<conio.h>Void main(){

int x;int mul,div;clrscr();printf(“Give one integer number\n”);scanf(“%d”,&x);mul = x << 1; /* left shift */div = x >> 1; /* right shift */printf(“multiplication of %d by 2 = %d\n”,x,mul);scanf(“division of %d by 2 = %d\n”,x,div);

}

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Bitwise Operators

Output:- Give one integer number 5 multiplication of 5 by 2 = 10 Division of by 2 = 2

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Other Special Operators

‘C’ language provides other special operator. They are:

Comma operator sizeof operator Arrow(->) operator dot operator * operator and & operator

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Other Special Operators

Comma operator:-(,) Comma operator is used to combine multiple

statements. It is used to separate multiple expressions. It has the lowest precedence. It is mainly used in for loop.

The expressions which are separated by comma operator are evaluated from left to right.

For example, the following statement z = (x=5, x+5); is equivalent to the statement sequence x = 5; z = x+5;

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Other Special Operators

sizeof operator:- sizeof operator is used to find our the storage

requirement of an operand in memory. It is an unary operator which returns size in bytes.

The syntax is sizeof(operand) For example, sizeof(float) returns the value 4 sizeof(int) return the value 2 The statement sequence, char c; sizeof(c); will return the value 1, because c is character type

variable.

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