FizzBuzz (the Classic Practice Problem)

This lesson covers solving FizzBuzz, a classic practice problem, in C, so you build the basics of combining a condition with a loop. It's for anyone searching "C FizzBuzz implementation."

FizzBuzz is a classic beginner-programming problem. Print numbers starting from 1, but print "Fizz" for a multiple of 3, "Buzz" for a multiple of 5, and "FizzBuzz" for a multiple of both. It's perfect practice for conditionals.

The example loops from 1 to 15, checking i % 15 == 0 first to prioritize multiples of 15, followed by checks for multiples of 3 and 5. The order of these checks is exactly what determines the correct result.

A common early mistake is the order of checks. Check multiples of 3 and 5 first, and a multiple of 15 would only print "Fizz" instead of "FizzBuzz" — you need to check the more restrictive condition first.

Simple as it looks, getting the order of conditions wrong breaks it, which is why it's a common basic-skills check in interviews and training.

📖 Reference code

#include <stdio.h>

int main() {
    for (int i = 1; i <= 15; i++) {
        if (i % 15 == 0) {
            printf("FizzBuzz\n");
        } else if (i % 3 == 0) {
            printf("Fizz\n");
        } else if (i % 5 == 0) {
            printf("Buzz\n");
        } else {
            printf("%d\n", i);
        }
    }
    return 0;
}

✍️ Your code

Type your code, then press "Run"

🧪 This site can't compile or run C directly, so it checks on the spot whether what you typed matches the reference code (scoring happens entirely in your browser — nothing is sent anywhere).