string[] array = { "cat", "dog", "perl" };

​

First Approach

    var index = Array.FindIndex(array, x => x == value);

Second Approach

    bool a = Array.Exists(array, element => element == "perl");

    bool c = Array.Exists(array, element => element.StartsWith("d"));

    bool d = Array.Exists(array, element => element.StartsWith("x"));

Linq Approach

    array.Contains("cat");

Fourth Approach

    int index = array.IndexOf(value);

using System.Linq; //Then you can use linq Contains() method

​

string[] printer = {"jupiter", "neptune", "pangea", "mercury", "sonic"};

if(printer.Contains("jupiter"))

{Console.WriteLine("'jupiter' is in the array");}