Nested Loop in C

Nested loop in C

A nested loop in a C is when the body of the loop contains another loop then the inner loop is known as a nested loop with the outer loop.

Since the body of one loop contains another loop there is an option of the loop is nested.

For example, the body of for loop contains another for loop then it is called nested for loop.

Syntax of a nested loop in C

Outer loop {      Inner loop           {                   } }

 

We commonly use nested for loop syntax for nested loop i.e.

for(initialization;condition;increase/decrease)       {            for(initialization; condition;increase/decrease)                         statement of inner loop;                   {                     }                      statement of the outer loop;          }

 

The inner loop always occupied the body of the outer loop in nested loop

nested for loop in C

One or more than one for loop contains the body of for loop then it is called nested for loop.

Commonly nested for loop is used in nested loop program because it is easy to use than another nested loop.

Syntax of nested for loop in C

for(initialization;condition;increase/decrease)       {            for(initialization; condition;increase/decrease)                       statement of inner loop;                   {                     }                       statement of the outer loop;          }

 

Example of nested for loop in C

Program

#include<stdio.h> #include<conio.h> void main() {      int i, j;      for(i=1;i<=5;i++) // outer loop      {                for(j=1;j<=i;j++) // inner loop           {               // statement of inner loop               printf("*\t"); // printing *           }               // statement of outer loop           printf("\n"); // moving crosser in next line      }      getch(); }

Output

        

nested while loop in C

When one or more while loops are used inside the while loop is known as nested while loop.

Syntax of nested while loop in C

while(condition) {     Initialization of outer loop;     while(condition)      {           statement of the inner loop;           inc/dec of the inner loop;           }          statement of the outer loop          inc/dec of the outer loop; }

 

Example of nested while loop in C

Program

#include<stdio.h> #include<conio.h> void main() {      int i=1; // outer loop initialization      int k=1;      while(i<=5) // outer loop      {           int j=1; // inner loop initialization           while(j<=5)// inner loop           {                // print the value of k               printf("%d\t", k);               j++; // inner loop inc/dec               k=k+1;           }           printf("\n");           i++; // outer loop inc/dec      }      getch(); }

 Output 

nested do-while loop in C

We can write an entire do-while loop structure inside another do-while loop structure. So do-while loop inside the do-while loop is called the nested do-while loop.

Syntax of nested do while loop in C

Outer loop initialization; do {          Inner loop initialization;         do         {           inner loop statement;        }          while(condition);         outer loop statement; }   while(condition);

 

Example of nested while loop in C

Program

#include<stdio.h> #include<conio.h> void main() {      int i=1; //initialization for outer loop      do      {           int j=1; // initialization for inner loop           do           {                // inner loop statement               printf("* ");               //inner loop inc/dec               j++;      }      while(j<=5); //inner loop condition      //outer loop statement      printf("\n");      //outer loop inc/dec      i++;     }     while(i<=5);// outer loop condition     getch(); }

Output

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