Major Difference
| for loop |
while loop |
| for (initialization; condition; increment/decrement) { statement(s); } |
while (condition) { statement(s); } |
| Initialization and increment/decrement expressions are specified within the loop header |
Initialization and increment/decrement need to be done manually |
| Typically used when you know the number of iterations in advance |
Used when you don't know the number of iterations in advance |
| The loop control variable is scoped to the loop body and header |
The loop control variable is scoped to the surrounding block |
| Can create infinite loops using for (;;) |
Can create infinite loops using while (1) or while (true) |
Example:
For Loop
#include <stdio.h>
int main() {
int n, factorial = 1;
printf("Enter a positive integer: ");
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
factorial *= i;
}
printf("Factorial of %d is %d\n", n, factorial);
return 0;
}
While Loop
#include <stdio.h>
int main() {
int n, sum = 0;
printf("Enter a positive integer: ");
scanf("%d", &n);
while (n != 0) {
sum += n % 10;
n /= 10;
}
printf("Sum of digits of %d is %d\n", n, sum);
return 0;
}
