Do-While Loop

The do-while loop is the cousin of while with one twist: it checks the condition after the body runs. That means the body always executes at least once.

The do-while Loop

Write do, then the body, then while (condition). The semicolon at the end is required — don't forget it.

#include 
int main() {
  int i = 1;
  do {
    printf("Count: %d\n", i);
    i++;
  } while (i <= 5);
  return 0;
}
    

Guaranteed Execution

Even if the condition is false from the start, the body still runs once. This is handy when you need something to happen before you check — like showing a menu or reading input.

#include 
int main() {
  int i = 10;
  do {
    printf("This runs once even though %d > 5\n", i);
    i++;
  } while (i <= 5);
  return 0;
}
    

while vs do-while

Use while when you might not need to run the body at all. Use do-while when the body must run at least once regardless of the condition.