Find if an element exists in an array

Topic description  

Different methods find whether an element exists in an array. (console application)

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

namespace find array element
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] myintArray = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 1, 2, 3, 4, 5, 6 };
            int result;
            //IndexOf(parameter 1, parameter 2) parameter 1 is the data to be found, parameter 2 is the element to be found
            //It is often used to judge whether there is an element in the array, return the index value if it exists, and return -1 if it does not exist
            result = Array.IndexOf(myintArray,8);
            if(result<0)
                Console.WriteLine("The element does not exist in the array");
            else
                Console.WriteLine("Find the element");

            Console.WriteLine("The index value of the first occurrence of 5 is {0}, and the index value of the last occurrence is {1}", Array.IndexOf(myintArray,5),Array.LastIndexOf(myintArray,5)) ;

            Console.WriteLine();
            //BinarySearch is used to find the index value of the first occurrence of the element. The method used is called dichotomy. If the element is not stored, a negative value is returned.
            int result2 = Array.BinarySearch(myintArray, 28);
            Console.WriteLine(result2);

            Console.WriteLine();
            //Array's Contains method is actually an implementation of the IList interface, so you need to convert the array to this object before using it
            //Converted format: ((System.Collections.IList)myintArray).Contains(8)
            //returns a boolean value
            bool mybool;
            mybool=((System.Collections.IList)myintArray).Contains(8);
            if(mybool)
                Console.WriteLine("The element exists");
            else
                Console.WriteLine("Does not exist");

        }
    }
}