Example: Prime Number or Not in C using For loop

// Prime Number or Not in C using For loop
#include <stdio.h>

// Function to check if it is a prime or not
int is_prime(int num)
{
    // If the input number is divisible by i, then the input number is not a Prime
    for (int i = 2; i < num; i++)
    {
        // If the input number is divisible by i, It's not a prime number
        if (num % i == 0)
            return 0;
    }

    // If there are no divisors, It's a prime number
    return 1;
}

// It's the main function of the program
int main()
{
    int num;

    // Step-1 Take input from the User
    printf("INPUT A NUMBER: ");
    scanf("%d", &num);

    // Step-2 Check if the input number is less than or equal to 1
    if (num <= 1)
        printf("%d IS NOT A PRIME NUMBER.\n", num);
    else
    {
        // Step-3 Call the is_prime() function to check whether the input number is prime or not
        if (is_prime(num))
            printf("%d IS A PRIME NUMBER.\n", num);
        else
            printf("%d IS NOT A PRIME NUMBER.\n", num);
    }

    return 0;
}