The meaning of this keyword in java

This keyword refers to the instance of the current object in Java. It has the following functions: 1. Access object properties or methods from non-static methods; 2. Call other constructors in the constructor; 3. Access non-static methods from static methods; 4. Distinguish between local variables and object properties; 5 . Access the outer class from the inner class.

The meaning of this keyword in Java

Introduction
this key A word in Java is a special variable that refers to the current instance of an object.

Function

1. Access object properties or methods from non-static methods:
This keyword allows accessing from non-static (instance ) method to access the current object's own properties or methods. For example:

<code class="java">public class Person {
    private String name;

    public void setName(String name) {
        this.name = name;
    }
}</code>

2. Call other constructors in the constructor:
This keyword can also be used in the constructor to call other constructors. This allows you to initialize the object with different parameters. For example:

<code class="java">public class Person {
    public Person(String name) {
        this(name, 0);
    }

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
}</code>

3. Access non-static methods from static methods:
Although static methods cannot directly access non-static properties or methods, you can use the this keyword to call non-static methods. static method. For example:

<code class="java">public class Person {
    private static void printName(Person person) {
        person.getName();
    }

    public void getName() {
        System.out.println(name);
    }
}</code>

4. Distinguish local variables and object properties:
If local variables and object properties have the same name, the this keyword can be used to explicitly reference the object properties. For example:

<code class="java">public class Person {
    private String name;

    public void setName(String name) {
        this.name = name;
    }

    public void printName() {
        String name = "局部变量";
        System.out.println(this.name);  // 引用对象属性
    }
}</code>

5. Accessing the external class in the inner class:
In the inner class, the this keyword refers to the inner class instance, and this.external class refers to the outer class instance. For example:

<code class="java">public class OuterClass {
    private String name;

    public class InnerClass {
        public void printName() {
            System.out.println(OuterClass.this.name);
        }
    }
}</code>

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