Nested Loop - C Tutorial

Nested Loop

C programming allows to use one loop inside another loop. The following section shows a few examples to illustrate the concept.

The syntax for a nested for loop statement in C is as follows −

 for ( init; testExpression; increment ) 
 {
   for ( init; testExpression; increment ) 
   {
      statement(s);
   }
	
   statement(s);
}

The syntax for a nested while loop statement in C is as follows −

while(testExpression)
{
   while(testExpression) 
   {
      statement(s);
   }
	
   statement(s);
} 

The syntax for a nested for Do While statement in C is as follows −

do 
{
   statement(s);
	
   do 
   {
      statement(s);
   }while( testExpression );
}while( testExpression );

Nested Loop Example

Multiplication Table from 1 to 5

#include <stdio.h>
int main()
{
    int num,i;
    for(num=1;num<=5;num++)
    {
        printf("Multiplication Table of %d\n",num);
        for (i = 1; i <= 10; i++)
             printf("%d*%d=%d\n", num, i, num * i);
    
    }
    return 0;
}

Output - Nested Loop Example

Multiplication Table of 1                                                                                               
1*1=1                                                                                                                   
1*2=2                                                                                                                   
1*3=3                                                                                                                   
1*4=4                                                                                                                   
1*5=5                                                                                                                   
1*6=6                                                                                                                   
1*7=7                                                                                                                   
1*8=8                                                                                                                   
1*9=9                                                                                                                   
1*10=10                                                                                                                 
Multiplication Table of 2                                                                                               
2*1=2                                                                                                                   
2*2=4                                                                                                                   
2*3=6                                                                                                                   
2*4=8                                                                                                                   
2*5=10                                                                                                                  
2*6=12                                                                                                                  
2*7=14                                                                                                                  
2*8=16                                                                                                                  
2*9=18                                                                                                                  
2*10=20                                                                                                                 
Multiplication Table of 3                                                                                               
3*1=3                                                                                                                   
3*2=6                                                                                                                   
3*3=9                                                                                                                   
3*4=12      
3*5=15      
3*6=18                                                                                                                  
3*7=21                                                                                                                  
3*8=24                                                                                                                  
3*9=27                                                                                                                  
3*10=30                                                                                                                 
Multiplication Table of 4                                                                                               
4*1=4                                                                                                                   
4*2=8                                                                                                                   
4*3=12                                                                                                                  
4*4=16                                                                                                                  
4*5=20                                                                                                                  
4*6=24                                                                                                                  
4*7=28                                                                                                                  
4*8=32                                                                                                                  
4*9=36                                                                                                                  
4*10=40                                                                                                                 
Multiplication Table of 5                                                                                               
5*1=5                                                                                                                   
5*2=10                                                                                                                  
5*3=15                                                                                                                  
5*4=20                                                                                                                  
5*5=25                                                                                                                  
5*6=30                                                                                                                  
5*7=35                                                                                                                  
5*8=40                                                                                                                  
5*9=45                                                                                                                  
5*10=50