this Keyword

• this can be used in a class to refer to the current calling object
  • if we have an object p1 and we call a method like p1.spam(), this refers to the p1 object
    • if we made another object of the same type p2 and called p2.spam(), this would refer to p2

public class Spam {
    private int snake;

    public Spam(int snake) {
        //           👇 refers to the local variable
        this.snake = snake;
        // 👆 refers to the instance variable
    }
}

• static methods cannot refer to this or instance variables
  • they are called with a class name, not an object!
    • there’s no object to refer to
• this can distinguish between parameter variables and instance variables
• this can be used anywhere you can use an object variable
  • you can pass it to another method as an argument!

Summary: 5.9.2

• this is a reference to the current object within a non-static method or constructor (the object whose method/constructor is being called)
• this.instanceVariable can distinguish between instance variables and local parameters if variables have the same names
• static methods cannot use this
• this can be used anywhere you would use an object variables
  • even in arguments!