C# String == Equals

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

namespace tmpTest
{
    class Program
    {
        static void Main(string[] args)
        {
            String str = "hello";
            if (str==args[0])
            {
                Console.WriteLine(str);
            }
            else
            {
                Console.WriteLine("not equal:"+str);
            }
           
        }
    }
}