RepetitionPractice4

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RepetitionPractice4 {
    class Program {
        static void Main(string[] args) {
            Console.WriteLine("[1] Summary of all number");
            Console.WriteLine("[2] Summary of odd number only");
            Console.WriteLine("[3] Summary of even number only");
            string[] choices = { "1", "2","3" };
            string selectedChoice = readInputInArray("Choose", choices);


            if (selectedChoice.Equals("1")) { sumAll(); }
            if (selectedChoice.Equals("2")) { sumOdd(); }
            if (selectedChoice.Equals("3")) { sumEven(); }

            Console.ReadKey();
        }


        static string readInputInArray(string name, string[] validInputs) {
            string input;
            while (true) {
                Console.Write("{0,-21} : ", name);
                input = (Console.ReadLine()).ToLower();
                if (validInputs.Contains(input)) {
                    return input;
                } else {
                    Console.SetCursorPosition(30, Console.CursorTop - 1);
                    Console.ForegroundColor = ConsoleColor.DarkRed;
                    Console.WriteLine("Invalid Input!!!");
                    Console.ResetColor();
                }
            }
        }
        static void line() {
            Console.WriteLine("==============================");
        }
        static void sumAll() {
            line();
            Console.WriteLine();
            int sum = 0;
            for (int i = 1; i <= 100; i++) {
                sum += i;
            }
            Console.WriteLine(" Summary of 1 - 100 is {0}", sum);
            Console.WriteLine();
            line();
        }
        static void sumOdd() {
            line();
            Console.WriteLine();
            int sum = 0;
            for (int i = 1; i <= 100; i+=2) {
                sum += i;
            }
            Console.WriteLine(" Summary of 1 - 100 is {0} (Odd Number Only)", sum);
            Console.WriteLine();
            line();
        }
        static void sumEven() {
            line();
            Console.WriteLine();
            int sum = 0;
            for (int i = 0; i <= 100; i+=2) {
                sum += i;
            }
            Console.WriteLine(" Summary of 1 - 100 is {0} (Even Number Only)", sum);
            Console.WriteLine();
            line();
        }
    }
}