C while Loop

The while loop in C is a control flow statement that repeatedly executes a block of code as long as a condition is true.

Syntax

while (condition) {
   // code block to be executed while condition is true
}

Example

#include <stdio.h>

int main() {
   int i = 1;

   while (i <= 5) {
      printf("%d ", i);
      i++;
   }

   return 0;
}

Output

1 2 3 4 5

Explanation

The while loop in C repeatedly executes a code block as long as the specified condition is true. The condition can be any valid C expression that evaluates to a boolean value (true or false).

In the above example, we use a while loop to print the values of i from 1 to 5. The while loop continues to execute the code block as long as i is less than or equal to 5.

Use

The while loop is commonly used in C programming for:

• Repeatedly executing a block of code until a certain condition is met.
• Reading input data until a specified sentinel value is encountered.
• Implementing an event loop in computer programs.

Important Points

• The condition specified in a while loop is evaluated before each iteration of the loop.
• If the condition is initially false, the code inside the loop block is never executed.
• It is important to define a condition in the while loop that will eventually become false to avoid infinite loops.
• The while loop can be replaced with the do-while loop if the condition needs to be evaluated at the end of each iteration.

Summary

The while loop in C is a powerful control flow statement that enables programmers to execute a code block repeatedly as long as a certain condition is true. Understanding the syntax and use cases for while loops is critical for creating efficient and reliable C programs.