The "this" keyword in Java is used as a reference to the current object, within an instance method or a constructor. Using it, you can refer the members of a class such as constructors, variables, and methods.
Assigning reference to "this"
According to the definition "this" is a keyword which acts as a reference to the current object (the object from whose constructor/method you are using it), its value id is fixed. Therefore, you cannot assign a new reference value to it. Moreover, it is just a keyword, not a variable.
Still, if you try to it assign a reference value to "this" it leads to a compilation error.
Example
In the following Java program, the class (ExampleClass) has two private variables name, age and, a parameterized constructor which instantiates these variables. From a method named display, we are trying to assign a new value to "this".
public class ExampleClass {
private String name;
private int age;
public ExampleClass(String name, int age){
this.name = name;
this.age = age;
}
public void display(){
this = new ExampleClass("krishna", 23);
}
}Compile-time error
On compiling, this program gives you an error as shown below −
ExampleClass.java:14: error: cannot assign a value to final variable this
this = new ExampleClass("krishna", 23);
^
1 error