How are this() and super() used with constructors?

this() is used to invoke a constructor of the same class.
super() is used to invoke a superclass constructor.

SuperThisDemo.java

class SuperClass
{
	int p;
	public SuperClass(){
		System.out.println("Super Class");
	}
	public SuperClass(int a)
	{	//this();
		this(20,40);
		System.out.println("Super Class with " + a);
	}
	public SuperClass(int a,int b)
	{
		System.out.println("Super Class with a and b " + a+ " "+b);
	}
	public void area(){
		System.out.println("Super Class with area ");
	}
	public void disp(){
		System.out.println("disp Super Class with p "+p);
	}
}
class SubClass extends SuperClass{	
	public SubClass()
	{	
		super(10); 	super.area(); super.p=20; super.disp();
		System.out.println("Sub Class");
	}
}
public class SuperThisDemo{
	public static void main(String s[])
	{
		(new SubClass()).disp(); //OR
		//SubClass a=new SubClass(); //a.disp();
	}
}