Usage of this in java

This keyword is a reference pointing to the object being executed. Main uses include: accessing instance variables and methods. Constructors refer to other constructors. Access external class from inner class. Access the nested class itself within a nested class. Access external classes from anonymous inner classes.

Usage of this keyword in Java

What is this keyword?

This keyword is a reference that points to the object being executed.

Purpose of this keyword

This keyword is mainly used for the following purposes:

• Access instance variables and methods: You can use the this keyword to access instance variables and methods declared in the class.
• Reference to other constructors in the constructor: You can use the this keyword in the constructor to call other constructors with different parameters.
• Accessing external classes in internal classes: In internal classes, you can use the this keyword to access members of external classes.
• Accessing the nested class itself in a nested class: In a nested class, you can use the this keyword to refer to the nested class itself.
• Accessing external classes in anonymous inner classes: In anonymous inner classes, you can use the this keyword to access members of the class containing the anonymous inner class.

Example of this keyword

class Person {
    private String name;

    public Person(String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }
}

In this example:

• Using this key in the constructor Words: In the constructor Person(String name), the this.name = name statement is used to assign the value of the name parameter to the instance variable name.
• Use the this keyword in the method: In the getName() method, the this.name statement is used to return the value of the name instance variable.

Notes on this keyword

• this keyword must be used in a non-static context: In a static method The this keyword cannot be used in or blocks.
• The this keyword is an implicit parameter: For non-static methods, the compiler will automatically pass the this object as the first parameter to the method. Therefore, the this keyword can be omitted in methods.

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