PRESENTATION

By:- Balwinder Singh

nested loops

CONTENTS

What is a Loop? Nested While loops. Do…..While loops. Nested For loops. Question.

WHAT IS A LOOP?

A loop is a programming structure that contains an executable block of code that repeats so long as a given condition is true/not true.

Good programmers include a way to satisfy the condition somewhere inside the executable block. loops

TYPES OF NESTED LOOPS

Nested While Loops. Do…..While Loops. Nested For Loops.

nested loops

NESTED WHILE LOOPS

WHILE loops may be nested, that is you can put a WHILE loop inside another WHILE loop.

However, one must start the inner loop after starting the outer loop and end the inner loop before ending the outer loop for a logically correct nesting.

EXAMPLE:- NESTED WHILE LOOPS

To print the following series:-

11 21 2 31 2 3 41 2 3 4 5

EXAMPLE:- NESTED WHILE LOOPS#include<stdio.h>#include<conio.h>main(){

int r=1,c=1;while (r<=5){c=1;while(c<=r){ printf(“%d”,c); c++; }printf(“\n”);r++;}getch();

}

DO……WHILE LOOP Executes the loop statement once and then

repeats the loop statement until the condition is zero (false).

Starts with a do statement and then tests the repetition condition in the while statement at the end of the loop.

Syntax:- do{ statements;}

while(condition);

LOGIC OF A DO….WHILE LOOPS

statement

true false

condition evaluated

The while Loop

EXAMPLE:- DO….WHILE LOOP

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

int a;do{printf(“Enter any number”);scanf(“%”,&a);if (a>=0)printf(“Number is positive”);elseprintf(“Number is Negative”);}while(a!=0);getch();

}

Accept any number from the user to print the number is positive or negative.

NESTED FOR LOOPS A for loop can contain any kind of

statement in its body, including another for loop.

The inner loop should have a different name for its loop counter variable so that it will not conflict with the outer loop.

EXAMPLE:- NESTED FOR LOOPS

Write a program to print the following series:-

12 34 5 67 8 9 10

EXAMPLE:- NESTED FOR LOOPS#include<stdio.h>#include<conio.h>main(){

int r,c,k=1;for (r=1;r<=4;r++){for (c=1;c<=r; c++) {printf(“%d”,k);k++;} printf(“\n”);}getch();

}

ANY QUESTIONS???

Do….WhileNested

While

Nested For