Difference between this and super in Java

this and super are reserved keywords in Java. this refer to current instance of a class while super refer to the parent class of that class where super keyword is used.

1. Java this keyword

this keyword automatically holds the reference to current instance of a class. It is very useful in scenarios where we are inheriting a method from parent class into child class, and want to invoke method from child class specifically.

We can use this keyword to access static fields in the class as well, but recommended approach to access static fields using class reference e.g. MyClass.STATIC_FIELD.

2. Java super keyword

Similar to this keyword, super also is a reserved keyword in Java. It always hold the reference to parent class of any given class.

Using super keyword, we can access the fields and methods of parent class in any child class.

3. Java this and super keyword example

In this example, we have two classes ParentClass and ChildClass where ChildClass extends ParentClass. I have created a method showMyName() in parent class and override it child class.

Now when we try to invoke showMyName() method inside child class using this and super keywords, it invokes the methods from current class and parent class, respectively.

public class ParentClass 
{	
	public void showMyName() 
	{
		System.out.println("In ParentClass");
	}
}

public class ChildClass extends ParentClass 
{
	public void showMyName() 
	{
		System.out.println("In ChildClass");
	}
	
	public void test() 
	{
		this.showMyName();
		
		super.showMyName();
	}
}

public class Main 
{
	public static void main(String[] args) 
	{
		ChildClass childObj = new ChildClass();
		
		childObj.test();
	}
}

Program output.

In ChildClass
In ParentClass

In this java tutorial, we learned what are this and super keywords. We also learned to use both keywords in java applications.

Happy Learning !!