Advanced Topics 3. Primes in Given Range

// Write a method that calculates all prime numbers in given range and returns them as list of integers.Write a method to print a list of integers. Write a program that enters two integer numbers (each at a separate line) and prints all primes in their range, separated by a comma.

namespace _03.PrimesInGivenRange
{
    using System;
    using System.Collections.Generic;

    public class PrimesInGivenRange
    {
        public static void Main(string[] args)
        {
            checked
            {
                int startNum;
                do
                {
                    Console.Write("Enter a non-negative Integer number: ");
                }
                while (!int.TryParse(Console.ReadLine(), out startNum) || startNum < 0);

                int endNum;
                do
                {
                    Console.Write("Enter other non-negative Integer number, Bigger from the First: ");
                }
                while (!int.TryParse(Console.ReadLine(), out endNum) || endNum <= startNum);

                List<int> primes = FindPrimesInGivenRangeAndPutThemInTheList(startNum, endNum);
                PrintListOfIntegers(primes);
            }
        }

        private static void PrintListOfIntegers(List<int> numsList)
        {
            checked
            {
                if (numsList.Count > 0)
                {
                    Console.WriteLine("The Prime Numbers In Given Range are:");
                    for (int i = 0; i < numsList.Count; i++)
                    {
                        Console.Write(numsList[i]);
                        if (i < numsList.Count - 1)
                        {
                            Console.Write(", ");
                        }
                    }

                    Console.WriteLine();
                }
                else
                {
                    Console.WriteLine("In Given Range No Any Prime Number!");
                    Console.WriteLine("(empty list)");
                }
            }
        }

        private static List<int> FindPrimesInGivenRangeAndPutThemInTheList(int start, int end)
        {
            checked
            {
                List<int> primes = new List<int>();
                for (int num = start; num <= end; num++)
                {
                    bool isPrimeNum = CheckTheIntegerNumberIsPrimeOrNot(num);
                    if (isPrimeNum)
                    {
                        primes.Add(num);
                    }
                }

                return primes;
            }
        }

        private static bool CheckTheIntegerNumberIsPrimeOrNot(int num)
        {
            checked
            {
                if (num < 2)
                {
                    return false;
                }
                else
                {
                    bool isPrime = true;
                    int maxDivider = (int)Math.Sqrt(num);
                    for (int i = 2; i <= maxDivider; i++)
                    {
                        if (num % i == 0)
                        {
                            isPrime = false;
                            break;
                        }
                    }

                    return isPrime;
                }
            }
        }
    }
}