When should I use “this” in a class?

Question

I know that this refers to a current object. But I do not know when I really need to use it. For example, will be there any difference if I use x i

Answer 1

The only need to use the this. qualifier is when another variable within the current scope shares the same name and you want to refer to the instance member (like William describes). Apart from that, there's no difference in behavior between x and this.x.