Frequently asked question asked by good companies on java programming language part-5

Question: How can we access the variables of super-classes without using "super" keyword.

Answer: We can access the variables of super-classes using "this" keyword instead of "super" keyword.

Lets understand how following code words =>

As we know the "this" keyword denotes current object in java programming language. And the type of any object can be type caste to any of its super-classes using the following syntax 

==> ((name-of-superclass)this)

after this syntax we can access the variable of super-classess like given syntax

==> ((name-of-superclass)this).variable-name


note: before using this code please create a "Java Project" in "Eclipse"


# save this class inside GreatGrandFather .java file #

public class GreatGrandFather {

String name = "Prithvi Raj Kapoor";

}

# save this class inside GrandFather .java file #

public class GrandFather extends GreatGrandFather {

String name = "Raj Kapoor";

}

# save this class inside Father .java file #

public class Father extends GrandFather {

String name = "Rishi Kapoor";

}

# save this class inside Son.java file #

public class Son extends Father {

String name = "Ranbeer Kapoor";

void showNames() {

System.out.print("The name of GreatGrandFather is ");
// access the variable of GreatGrandFather

// here i am converting the type of Son's object to the GreatGrandFather

System.out.println(((GreatGrandFather)this).name);

System.out.print("The name of GrandFather is ");

// access the variable of GrandFather

// here i am converting the type of Son's object to the GrandFather

System.out.println(((GrandFather)this).name);

System.out.print("The name of Father is ");

// access the variable of Father

// here i am converting the type of Son's object to the Father

System.out.println(((Father)this).name);

// note: we can also access the variable of class Father using "super"
       //  keyword, example "super.name"

System.out.print("The name of Son is ");

// access the variable of Son

// note: we can also access the variable of class Son using "this" keyword,
        // example "this.name"

System.out.println(((Son)this).name);

}

}

# save this class inside UseOfThisKeyword .java file #

public class UseOfThisKeyword {

public static void main(String[] args) {

// create object of class Son
        Son son = new Son();

// call the method using object-name "son" of class Son
        son.showNames();

}

}