Loops in C language

After decision-making statements there comes the loops in C languages. In a loop, a block of code is executed sequentially a number of times mentioned in the statement. For example, the first statement will execute first, then second, and so on.

There are the following types of loops in the C language. Let's know in brief about them.

Sr.No.

Loop Type & Description

  • while loop

While loop continuously repeats statements while a given condition is true and tests the condition before executing the loop body.

  • for loop 

For loop executes a sequence of statements multiple times and follows the code that manages the loop variable.

  • do-while loop

It is quite similar to a while statement, except that it checks the condition at the end of the loop body.

  • nested loops

You can use one or more than one loop inside any other while, for, or do-while loop.

 

Infinite Loops

The loop in C becomes an infinite loop when a condition never becomes false. By making a condition null you can easily make an infinite loop

 

 

We can terminate an infinite loop by pressing Ctrl + C keys.

 

for loop example

 

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

   int a;
	
   /* for loop execution */
   for( a = 1; a < 10; a = a + 1 ){
      printf("value of a: %d\n", a);
   }
 
   return 0;
}

 

The above loop will execute until the value of a reaches to 9. When it increment to 10 then the condition will not saticifies and breaks the loop.

 

Output

value of a: 1
value of a: 2
value of a: 3
value of a: 4
value of a: 5
value of a: 6
value of a: 7
value of a: 8
value of a: 9

 

Loop Controll Statements

This Loop controll statements will breaks the current loop and finish the current executed function.

C Language has below controll statments

  • break
  • continue
  • goto

 

break controll example

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

   /* local variable definition */
   int a = 1;

   /* while loop execution */
   while( a < 10 ) {
   
      printf("value of a: %d\n", a);
      a++;
		
      if( a > 5) {
         /* terminate the loop using break statement */
         break;
      }
   }
 
   return -1;
}

 

The above while loop will executes until the value of a increments to 5. when it reached 5 the break controll statement will stop the current loop  

 

output

value of a: 1
value of a: 2
value of a: 3
value of a: 4
value of a: 5