using System;

public class Program

{

    public static void Main()

    {

        // Evan Lucier

        // Date started:    April 17th

        // Date Ended:      April 20th

        // Prime number tester

        // This is a system where you enter a desired number and it will display whether or not it is prime 

        int num = 0;            // introduces the variable num as 0 value

        int remainder =0;       // introduces the variable remainder as 0 value

        Start:                  // Takes user back here if they wish to use the program again

        Console.WriteLine("Welcome to the prime number tester!");   // Title

        Console.WriteLine("Enter in a number here:");               // User is asked to enter a desired number to be tested

        num = Convert.ToInt32(Console.ReadLine());                  // User enters in desired number, represented as the variable "num"

        for (int primenum = 2 ; primenum <= (num - 1) ; primenum++) // For loop for calculating to get remainders based off of the number input 

                                                                    // Introduces the variable primenum as a value of 2

        {   

            remainder = num % primenum;         // Calculates the remainder by doing num % primenum

            if (remainder == 0)                 // if statement regarding the value of remainder being 0. If true, executes the following statements below

            {

                Console.WriteLine(num + " is not a prime number.");     // Displays num input and a statement saying it is not a prime number

                Console.WriteLine();

                goto Start;         // Takes user back to start to use program again

            }   

        }

​

        Console.WriteLine(num + " is a prime number.");     // If the if statement above was false, then display the num input and the statemeny saying the num is a prime number

        Console.WriteLine();

        goto Start;                 // Takes user back to start to use program again

    }

​

}