super keyword
super is a keyword that refers to the object of super class. Generally, we write sub class variables, constructors and methods in a class. Whenever data members of a class and formal parameters of a method or constructor is existing with same name then system will get confused to overcome this problem “super.†can be useful.
super class variables
class Test1
{
int a=10;
int b=20;
};
class Test extends Test1
{
int a=100;
int b=200;
void add(int a,int b)
{
System.out.println(a+b);
System.out.println(this.a+this.b);
System.out.println(super.a+super.b);
}
public static void main(String[] args)
{
Test t=new Test();
t.add(1000,2000);
}
};
Output :
Super class methods
class Parent
{
void m1()
{
System.out.println("parent class method");
}
};
class Child extends Parent
{
void m1()
{
System.out.println("hi");
}
void m2()
{
this.m1();
System.out.println("hello");
super.m1();
}
public static void main(String[] arhs)
{
Child c=new Child();
c.m2();
}
};
Output :
output:hi,,hello,,parent class method
Super class constructors
class Test1
{
Test1(int i,int j)
{
System.out.println(i+j);
}
};
class Test extends Test1
{
Test(int i)
{
super(100,200);
System.out.println(i);
}
public static void main(String[] args)
{
Test t=new Test(10);
}
}
Output :
Note :-
  inside the constructors it is possible to call only one constructor at a time that calling must be first statement of the constructor.
