C Do-While Loop

The do-while loop in C is used when you want to ensure that a block of code executes at least once before checking a condition. Unlike the while loop, the condition in a do-while loop is evaluated after the execution of the code block.

1. Do-While Loop Syntax

The do-while loop checks the condition after the loop's body has been executed. This guarantees that the code inside the loop will always run at least once.

                        
do {
    // code to be executed
} while (condition);
                        
                    

                        
#include <stdio.h>
int main() 
{
    int i = 0;
    do {
         printf("%d\n", i);
         i++;
       } 
       while (i < 5);
    return 0;
}
                        
                    

2. Key Points of the Do-While Loop

• The code inside the do block will execute at least once, even if the condition is false.
• The condition is checked after the execution of the loop's body, ensuring at least one iteration.
• If the condition is false after the first execution, the loop will terminate.

3. When to Use the Do-While Loop

• Use the do-while loop when you need the loop to run at least once, regardless of whether the condition is initially true or false.
• It is particularly useful when the loop's body contains code that must be executed before the condition is checked (e.g., input validation).

4. Comparison with Other Loops