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CSharp · Console

/Program.cs

using System;	

static class ArrayExtensions
{
	public static int IndexOf<T>(this T[] array, T value)
    {
 		return Array.IndexOf(array, value);
    }	
}

public class Program
{
	public static void Main()
	{
		// Usage
		int[] array = { 9,8,7,6,5 };

		var index = array.IndexOf(7);

		Console.WriteLine(index); // Prints "2"
	}
}