Fizz Buzz in C

Published on 05 October 2020 (Updated: )

Fizz Buzz in C

In this article, we will look into implementing FizzBuzz using C.

How to Implement the Solution

The rules to be applied on this problem are:

Write a program that prints the numbers 1 to 100. However, for multiples of three, print “Fizz” instead of the number. Meanwhile, for multiples of five, print “Buzz” instead of the number. For numbers which are multiples of both three and five, print “FizzBuzz”

Now, let us take a look at the code for FizzBuzz in C.

#include <stdio.h>

int main(void){
    for (unsigned int i = 1; i <= 100; i++) {
        if (i % 15 == 0) {
            puts("FizzBuzz");
        } else if (i % 3 == 0) {
            puts("Fizz");
        } else if (i % 5 == 0) {
            puts("Buzz");
        } else {
            printf("%u\n", i);
        }
    }
    return 0;
}

Let’s understand this code block by block.

Main Function

#include <stdio.h>

Here, we are including Standard Input/Output header file(.h files) using include directive inorder to use printf() and puts() function later in the program. 
 

int main(void){

In C, we declare a function using general form:

return_type function_name(parameter){
  ...
}

So, here we are declaring main function with return type integer and void as a parameter, i.e., no input from the user.

For Loop

for (unsigned int i = 1; i <= 100; i++) {
}

In this block, we first created a for loop initializing i as an unsigned integer(non-negative integers) as 1 and increasing it by 1 everytime the for loop iterates. This for loop will iterate until the value of i is equal to 100.

Before moving onto if-elseif statements, we should consider puts() and printf() functions. puts() writes null-terminated string into stdout(standard output - a file descriptor where a process can write output) and adding a newline at the end. printf() prints formatted string. In this program, we are using %u as a format specifier for unsigned integers.

Control flow

if (i % 15 == 0) {
    puts("FizzBuzz");
} else if (i % 3 == 0) {
    puts("Fizz");
} else if (i % 5 == 0) {
    puts("Buzz");
} else {
    printf("%u\n", i);
}

Now, variable i which we initialized in for loop, will check for following conditions:

Finally, return 0; returns 0 to main program, which indicates zero errors.

How to Run the Solution

To run a C program, we need to install GCC compiler and run the following command in terminal.

gcc -o fizz-buzz fizz-buzz.c
./fizz-buzz

Another handy option is to compile and run using online C Compiler such as OnlineGDB, Repl

Further Reading