Why do s1 and s2 stay the same despite being passed through the swap method? If you could explain with the java code please.

What is the output of the following code? Java C# class Main { public static void swap(String str1, String str2) { String holdString; holdString = str1; str1 = str2; str2 = holdString; } class MainClass { public static void swap(string str1, string str2) { String holdString; holdString = str1; str1 = str2; str2 = holdString; } public static void main(String[] args) { String s1 = "Computers": String s2 = "Rock"; swap(s1, s2); System.out.println(s1+""+s2); } } public static void Main (string[] args) { string s1 = "Computers"; string s2 = "Rock"; swap(s1, s2); Console.WriteLine(s1+""+s2); } } Computers Rock Rock Computers Computers Computers Rock Rock