MethodPractice6

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

namespace MethodPractice6 {
    class Program {
        static string fileName = "Employee.txt";

        static void Main(string[] args) {
            string empID = readEmployeeID();
            string empName = readLine("Name");
            string[] validGenders = { "m", "f" };
            string empGender = readInputInArray("Gender", validGenders);
            double salary = readInputNumber("Salary");
            int startYear = readInputRange("Start Year", 2000, 2559);

            saveFile(empID, empName, empGender, salary, startYear);

            Console.WriteLine("\nPress any to close program...");
            Console.ReadKey();
        }

        static void saveFile(string empID, string empName, string gender, double salary, int startYear) {
            try {
                StreamWriter fw = new StreamWriter(fileName,true);
                fw.WriteLine("{0}/{1}/{2}/{3}/{4}", empID, empName, gender, salary, startYear);
                fw.Close();
            } catch (Exception) {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine("Couldn't Write File.");
            }
        }

        static string readLine(string name) {
            Console.Write("Input {0} : ", name);
            return Console.ReadLine();
        }

        static bool checkEmpID(string empID) {
            if (empID.Length == 4) {
                if (empID[0].Equals('E')) {
                    try {
                        int empIDIdx = int.Parse(empID.Substring(1, 3));

                        return true;
                    } catch (Exception) { }
                }
            }
            return false;
        }

        static string readEmployeeID() {
            string empID = "";
            do {
                Console.Write("Input EMP ID : ");
                empID = Console.ReadLine();
            } while (!checkEmpID(empID));
            return empID;
        }

        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;
                }
            }
        }

        static int readInputNumber(string name) {
            while (true) {
                try {
                    Console.Write("Input {0} : ", name);
                    return int.Parse(Console.ReadLine());
                } catch (Exception) { }
            }
        }

        static int readInputRange(string name, int min, int max) {
            int num;
            while (true) {
                try {
                    Console.Write("Input {0} : ", name);
                    num = int.Parse(Console.ReadLine());
                } catch (Exception) {
                    num = min - 1; //Workaround
                }
                if ((num >= min && num <= max)) {
                    return num;
                }
            }
        }
    }
}