Please explain “this” to me

Question

I\'ve read hundreds of explanations on \"this\" in java and I\'m really having trouble grasping it. I\'m learning android and java side-by-side, I know it\'s harder that wa

Answer 1

this refers to the current Object's reference.

Read this for more understanding.

To give an example from the link:

public class Point {
    public int x = 0;
    public int y = 0;

    //constructor
    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

Here, to differentiate from the x of the Point and x of the argument, you need to tell the compiler the difference. You achieve that using this. Meaning, when I write, this.x it means, the particular x belongs to the current Object, which in the case is Point.

Taking example from the code that you have provided:

AlertDialog.Builder(this)

AlertDialog.Builder() takes in a Context as a parameter in its constructor. But here, you don't do Context someContext = new Context(); and pass that as the parameter, because you simply need to pass your current Activity's Context. So you simply use this.