using System;

public class Program

{

    public static void Main()

    {

        int[] intArray = new int[] {1,2,3,4,5};

        Console.WriteLine("Before");

        foreach(var number in intArray)

        {

            Console.WriteLine(number);

        }

        MultiplyContentBy2(intArray);

        Console.WriteLine("After");

        foreach(var number in intArray)

        {

            Console.WriteLine(number);

        }

    }

    private static void MultiplyContentBy2(int[] sourceArray)

    {

        for(int i = 0; i< sourceArray.Length; i++)

        {

            sourceArray[i] = sourceArray[i] * 2;

        }

    }

}