Parameter modifiers

ref

Pass a parameter by reference.

// value type var i = 10; Method0(i); // 10 Method1(ref i); // 11 void Method0(int i) => i++; // pass the value type parameter by value (copy) void Method1(ref int i) => i++; // pass the value type parameter by reference // reference type var item = new Item("init name"); Method2(item); // init name Method3(ref item); // new name 3 // pass the reference type parameter by value: the reference is passed by value (copy) // if the parameter is overwritten (the copy of the reference is overwritten), it doesn't affect the initial object void Method2(Item item) => item = new("new name 2"); // pass the reference type parameter by reference: the reference is passed by reference // if the parameter is overwritten (the initial reference is overwritten), it does affect the initial object void Method3(ref Item item) => item = new("new name 3");

out

Allow to initialize the parameter in the method.

Method5(out var j); // 5 void Method5(out int i) => i = 5;