c do-while loop

do-while LOOP Construct

In a real time situation, while an iteration is taking place, if the condition

needs to be evaluated at the end of each iteration, then do-while Loop is

proposed.

Syntax:

do

{

program statements;

}while(condition);

The Program statement is executed first.

The Condition is evaluated to check TRUE or FALSE.

If TRUE loop continues executing program statement once again.

If FALSE loop terminates handling remaining tasks.

Program to calculate average of N numbers

Program

#include<stdio.h>

void main()

{

int n, count = 1;

float x, avg, sum = 0;

printf("\nHow many Numbers to Average : ");

scanf("%d", &n);

do

{

printf("\nEnter Value for X = ");

scanf("%f", &x);

sum += x;

++count;

}while(count <= n);

avg = sum / n;

printf("\nThe Average is %0.2f", avg);

}

for – loop Construct

The ‘for’ loop construct has the fallowing properties:

It includes an EXPRESSION that specifies an INITIAL VALUE for an INDEX.

The SECOND EXPRESSION determines whether or not the LOOP SHOULD

CONTINUE or TERMINATE.

The THIRD EXPRESSION allows the INDEX to be MODIFIED at the END OF

EACH PASS.

Syntax:

For(exp1; expr2; expr3)

{

Programming Statements;

}

1. Expr1: It is used to INITIALIZE some parameter for LOOP.

2. Expr2: It represents a CONDITION that must be TRUE for the LOOP to

CONTINUE

3. Expr3: It represents the EVOLUTION at the END of EACH PASS.

‘for’ LOOP is mostly used when we want to execute a loop for a fixed

number of times.

The control variable need not be initialized and incremented separately

inside or outside the loop body.

All the three expressions in the for loop are separated by semi-colon.