Super Keyword

Use One: The first use of super is to refer to a super class variable or method which is hidden (variable) or overridden (method) in the super class.
Super can be written only in now static.

class A
{
    int x = 10;
    void met1()
    {
        System.out.println(x);
    }
}

class Super1 extends A
{
    int x=100;
    void met1()
    {
        System.out.println("Super1");
        System.out.println(super.x);
        super.met1();
    }

    public static void main(String args[])
    {
        Super1 p = new Super1();
        p.met1();
        System.out.println(p.x);
    }
}

OUTPUT :    Super1
        10
        10
        100


Use Two: The second use of super is to call a specific super class constructor from the subclass’s constructor by passing appropriate arguments.
The call to super should be in the first line of the sub class’s constructor.

class Area
{
    int l, b;
    Area(int a, int b)
    {
        l=a;
        this.b = b;
    }
    void calArea()
    {
        int c = l * b;
        System.out.println("Area : "+c);
    }
}

class Volume extends Area
{
    int h;
    Volume(int a, int b, int c)
    {
        super(a,b);
        h=c;
    }
    void calVolume()
    {
        int v = l * b * h;
        System.out.println("Volume : " + v);
    }
    public static void main(String args[])
    {
        Volume x = new Volume(10,20,30);
        x.calArea();
        x.calVolume();
    }
}

OUTPUT :  Area    : 200
                   Volume    : 6000