Programming In C++ Spring Semester 2013 Lecture 3 Programming In C++, Lecture 3 By Umer Rana

Programming In C++

Spring Semester 2013Lecture 3

Programming In C++, Lecture 3 By Umer Rana

• What is counter?

• What is repeat?

• What is decisions?



Assignment OperatorsAssignment operators abbreviate assignment expressions• +=• -=• *=• /=• %=Examples :If a=10

a += 1 or (a = a + 1) output is 11a -= 1 or (a = a - 1) output is 9a *= 1 or (a = a * 1) output is 10a /= 1 or (a = a / 1) output is 10a %= 1 or (a = a % 1) output is 0


Increment / Decrement OperatorsIncrement operator (++)

Can be used instead of a+=1 or a=a+1

Decrement operator (--)Can be used instead of a-=1 or a=a-1

Example:If a equals 10, then

printf( "%d", ++c );Output 11

printf( "%d", c++ ); Output 10In either case, c now has the value of 10


Decision Making

Equality operators==!=

Relational operators<><=>=


Data Flow Diagram (DFD)

Expression

Decision

Process

Show Flow

LoopsTo execute a set of instructions repeatedly until a particular condition is being satisfied.

Three types of looping statements are there1) For Loop2) While Loop3) Do while Loop


LoopsRequires

1. The name of a counter variable 2. The initial value of the counter variable3. A condition that tests for the final value of the counter

variable (i.e., whether looping should continue)4. An increment or decrement by which the counter

variable is modified each time through the loop run


LoopsFor Loop

For loop in C is the most general looping construct. In for looping statement allows a number of lines represent until the condition is satisfied.

Syntax of for loop expression:For Loop expression is divided by semicolons into three separate expressions: the “Initialize expression”, the “test expression”, and the “Increment/Decrement expresssion”

for(Initialize counter variable ; Condition ; Increment/Decrement the counter variable)

{ Body of the for loop }


For Loop DFD


Initialization expression

Test Expression /Condition

Body of loop

Increment / Decrement Expression

ExitFalse

True

Loops


Example: Print number 1 to 10 this way:

123456789

10

void main(){

printf (“1\n”);printf (“2\n”);printf (“3\n”);printf (“4\n”);printf (“5\n”);printf (“6\n”);printf (“7\n”);printf (“8\n”);printf (“9\n”);printf (“10\n”);

}

Loops


Example: #include <stdio.h>

void main(){

int counter;for(counter = 1; counter <= 10;

counter++ )

printf( "%d\n", counter );

}

OutPut12345678910

Loops


Example of Multiple Statement:

#include <stdio.h>void main(){

int counter, total=0;for(counter = 1; counter <= 10; counter++ )

{ total=total + 1;

printf( “counter=%d, total=%d\n", counter,total );

}}

OutPutCounter = 1 Total = 1Counter = 2 Total = 2Counter = 3 Total = 3Counter = 4 Total = 4Counter = 5 Total = 5Counter = 6 Total = 6Counter = 7 Total = 7Counter = 8 Total = 8Counter = 9 Total = 9Counter = 10 Total = 10

Loops While Loop

While loop in C is the other most general looping construct. The while loop statement executes as long as a specified condition is true.

Syntax of while loop expression:while ( condition ) { Code to execute, while the condition is true. }

while(condition) {

statement(s); }


Loops While Loop DFD


LoopsExample


#include <stdio.h>

void main () {

// Local variable declaration: int a = 10; // while loop execution while( a < 20 ) {

printf(“value of a is %d”,a);a++;

}}

LoopsExample


#include <stdio.h>

void main () {

// Local variable declaration: int a = 0; char ch=‘a’;// while loop execution

while (ch != ‘\r’){

printf(“Enter a character: \n”);ch=getche();printf(“Entered Character is %c\n”,ch);

}}

Loops

do while Loop do… While loop is checks its condition at the bottom of the loop. A do...while loop is similar to a while loop, except that a

do...while loop is execute at least one timeSyntax of do..while loop expression:

do {

statement(s); }

while( condition );


Loops

do while Loop


LoopsExample


#include <stdio.h>

void main () {

// Local variable declaration: int a = 10; // while loop execution do{

printf(“value of a is %d”,a);a++;

} while( a < 20 ) ;

}

Loops Nested Loop One loop inside another loop . In nested loop the inner loop is executed first and then outer.

Syntax of for Nested Loop:for ( init; condition; increment ) {

for ( init; condition; increment ) {

statement(s); }

statement(s); }


LoopsSyntax of while Nested Loop:

while(condition) {

while(condition) {

statement(s); }

statement(s); }


LoopsSyntax of do..while Nested Loop:

do {

statement(s); do

{ statement(s);

} while( condition );

}while( condition );


LoopsLoop Control Statements:Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed


break statement Terminates the loop or switch statement and transfers execution to the statement immediately following the loop or switch.

continue statement Causes the loop to skip the remainder of its body and immediately retest its condition prior to reiterating.

goto statement Transfers control to the labelled statement.

http://www.tutorialspoint.com/cprogramming/c_break_statement.htm

http://www.tutorialspoint.com/cprogramming/c_continue_statement.htm

http://www.tutorialspoint.com/cprogramming/c_goto_statement.htm

http://www.tutorialspoint.com/cprogramming/c_goto_statement.htm

LoopsBreak Statements:

– When the break statement is encountered inside a loop, the loop is immediately terminated and program control resumes at the next statement following the loop.

– If you are using nested loops ( ie. one loop inside another loop), the break statement will stop the execution of the innermost loop and start executing the next line of code after the block


true

false

LoopsBreak Statements:#include <stdio.h> Void main () {

/* local variable definition */ int a = 10; /* while loop execution */ while( a < 20 )

{ printf("value of a: %d\n", a); a++; if( a > 15)

{ /* terminate the loop using break statement */ break;

} }

}Programming In C++, Lecture 3 By Umer Rana

LoopsContinue Statements: continue forces the next repetition of

the loop to take place, skipping any code in between.


true

false

LoopsContinue Statements:#include <stdio.h> Void main () {

/* local variable definition */ int a = 10; /* while loop execution */ while( a < 20 )

{ printf("value of a: %d\n", a); a++; if( a == 15)

{ a++;

continue; }

} }


LoopsGoto Statements:A goto statement provides an unconditional jump from the goto to a labeled statement in the same function.

Syntex

goto label

.. . label: statement;


true

false

LoopsGoto Statements:#include <stdio.h>void main () {

/* local variable definition */ int a = 10; /* do loop execution */ LOOP:do

{ if( a == 15)

{ /* skip the iteration */ a ++; goto LOOP;

} printf("value of a: %d\n", a); a++;

}while( a < 20 ); }


Quiz• How many type of loops we have?• What is the expression of the for loop?• What is the expression of the while loop?• What is the expression of the do.. while loop?• What is nested loop?• What break statement does?• What continue statement does?• What goto statement does?• What you have to do?


Assignment # 1Q1. Differentiate between IDE and Command-Line Development System. Explain the program execution process and environment with the help of diagram?

Q2. Explain the following terms with appropriate examples:• Getche()• Printf()• Scanf()


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Programming In C++ Spring Semester 2013 Lecture 3 Programming In C++, Lecture 3 By Umer Rana