Java Buzz Forum - Difference between this and super keywords in Java

this and super are two special keywords in Java, which is used to represent current instance of a class and it's super class. Java Programmers often confused between them and not very familiar with there special properties, which is asked at various core Java interviews. Couple of questions, which I remember about this and super keyword is that, Can we reassign this in Java? and difference between this and super keyword in Java. Do you want to try that? Ok, I am not giving answer now, rather I will let you know answer at the end of this post. As I said in first line, main difference between this and super in Java is that, this represent current instance of a class, while super represent current instance of parent class. Now where does this and super variables used, well you might have seen examples of calling one constructor from other i.e. constructor chaining, that's achieved by using this and super keyword. You can use this() to call no argument constructor of same class, while super() to call no argument or default constructor of parent class. By the way, call is not limited to only no argument constructor, you can call any constructor by passing appropriate parameters. We will see example of using this and super in a while. Another use of this and super in Java is for accessing instance variables of a class and it's parent. By the way, you can also access them even without prefixing super and this, if they are not ambiguous in current block e.g. if there is no local variable of same name exists in that block, but in case of ambiguity they provide explicit reference and are more readable. Classic example of using this is inside a constructor, which accepts a parameter of same name as an instance variable. In this post, we will learn about more differences between super and this in Java and take a look at some of the use cases.


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