Try Catch C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace try_Catch
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                String[] city = { "Dhaka", "Dinajpur", "Rangpur" }; // here key 0 for Dhaka, 1 fro DInajpur, 2 for Rangpur

                MessageBox.Show(city[3]); // Should get error for key 3 which is not exist in array
            }

            catch
            {
                MessageBox.Show("There is an Error");

            }

            //code by Touhid
        }
    }
}