dataTypes3.cs

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        string[] particles = new string[] { "electron", "proton", "neturon", null, null };
        
        particles.SetValue("muon", 3);
        particles.SetValue("photon", 4);
		
        foreach (string particle in particles)
        {
            Console.WriteLine(particle);
        }
    }
}