“this” Keyword in Java
- this keyword is a reference to the current object within instance method or a constructor.
- this () is used to invoke current class constructor.
- this can also be used to pass an argument in the method call.
Example: Sample program for using this keyword
public class Rectangle
{
int length, width;
Rectangle(int length, int width)
{
this.length = length;
this.width = width;
}
int areaCal()
{
return (length*width);
}
public static void main(String args[])
{
Rectangle rec = new Rectangle(53, 45);
int area = rec.areaCal();
System.out.println ("Area of Rectangle: "+area);
}
}
Output:
Area of Rectangle: 2385
Example: Sample program for constructor calling
class ConDemo
{
int empId;
String name;
ConDemo()
{
System.out.println("Default Constructor:");
}
ConDemo(int empId, String name)
{
this(); // invoked default constructor
this.empId = empId;
this.name = name;
}
void show()
{
System.out.println("Employee ID: "+empId+" Name: "+name);
}
public static void main(String args[])
{
ConDemo con = new ConDemo(100,"XYZ");
con.show();
}
}
Output:
Default constructor:
Employee ID: 100 Name: XYZ
