This Keyword

Inside the class body this refers to the current class object.

It can be used to access / modify members and call functions inside the class.

Example

class Rectangle { private double width; double height; void setWidth(double width) { // Modify object's member: this.width = width; } void setHeight(double height) { // Modify object's member: this.height = height; } double calcArea() { // Access class members: return this.height * this.width; } public void printData() { System.out.println("Width = " + this.width); System.out.println("Height = " + this.height); // Access class function: double area = this.calcArea(); System.out.println("Area = " + area); } } public class Main { public static void main(String[] args) { Rectangle rectangle = new Rectangle(); rectangle.setWidth(3); rectangle.setHeight(2); rectangle.printData(); } }

Output:

Width = 3.0 Height = 2.0 Area = 6.0

Explanation:

• At lines 10, 16 values are set to the members width and height.
• At lines 22, 28 and 29 members are accessed.
• At line 32 a class function is called.
• At line 40 an object is created.
• At lines 42 and 43 in which width and height are set, this points to the object created at line 40.