Program.cs

using System;

class Program
{
    static void Main(string[] args)
    {
        KodePos table_Kodepos = new KodePos();
        Console.WriteLine("=== GET KODE POS BATUNUNGGAL===");
        table_Kodepos.getKodepos("Batununggal");
        Console.WriteLine("==== GET ALL KODE POS ====");
        table_Kodepos.getAllkodepos();




    }

}
class KodePos
{

    Dictionary<string, string> dic = new Dictionary<string, string>() {
            {"Batununggal","40266"},
            {"Kujangsari","40287"},
            {"Mengger"  ,"40267"},
            {"Wates"    ,"40256"},
            {"Cijaura"  ,"40287"},
            {"Jatisari" ,"40286"},
            {"Margasari","40286"},
            {"Sekejati" ,"40286"},
            {"Kebonwaru","40272"},
            {"Maleer"   ,"40274"},
            {"Samoja"   ,"40273"} };

    public void getKodepos(string kel)
    {
        if (dic.ContainsKey(kel))
        {
            Console.WriteLine(kel + " : " + dic[kel]);
        }
        else
        {
            Console.WriteLine(kel + " tidak ditemukan");
        }
    }

    public void getAllkodepos()
    {
        foreach (KeyValuePair<string, string> ele1 in dic)
        {
            Console.WriteLine("{0} \t\t {1}", ele1.Key, ele1.Value);
        }
    }
}