Difference between passing a reference type and a value type as argument to a method

Question

Just got this confusion running in my mind throughout the day. I am very much confused between reference and value type being passed to a method.

Say I have 2 classes

Answer 1

Beside Reference Type and Value Type, there are Mutable Type and Immutable Type.

Immutable means that object cannot and will not be changed after initialization. As a result, your statement only produces new string but does not modify original string.

s += "Hi";

The hello string object remains hello. Change is that s is assigned with a new object helloHi.

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You are unfortunate enough using string as an example.

Try to use mutable types like StringBuilder in your example.

public class C
{
    public static void Main(string[] args)
    {
        StringBuilder s = new StringBuilder("hello");
        StringBuilder w = Changestring(s);
        StringBuilder x = s;
    }

    private static StringBuilder Changestring(StringBuilder s)
    {
        s.Append("Hi");
        return s;
    }
}