How to use init() in java

The init() method in Java is used to perform initialization before calling the class constructor. It is usually used to: initialize member variables, set default values ​​or load external data. Perform initialization tasks that the constructor cannot handle, such as connecting to a database or loading configuration. Override in a subclass to perform subclass-specific initialization tasks.

Usage of init() in Java

init() The method is in Java Method used to initialize member variables of a class or perform other initialization tasks. It is called before the class constructor and is usually used to set the object's default value or perform other preparations.

Usage method

init() The syntax of the method is as follows:

public void init() {
    // 初始化代码
}

When to use it

init() The method is usually used in the following situations:

• Initialize member variables: Set default values ​​for object member variables or Load values ​​from external sources.
• Perform initialization tasks: Perform additional initialization tasks that the constructor cannot handle, such as connecting to a database or loading a configuration.
• Override in subclasses: Override the init() method in subclasses to perform subclass-specific initialization tasks.

Example

The following is an example using the init() method:

public class Person {
    private String name;
    private int age;

    public Person() {
        init();
    }

    public void init() {
        name = "无名氏";
        age = 0;
    }
}

Advantages And Disadvantages

There are some advantages and disadvantages of using the init() method:

Advantages:

• Perform initialization before the constructor to ensure that member variables are properly initialized before the constructor uses them.
• Can be easily overridden in subclasses, allowing subclasses to perform their own initialization tasks.

Disadvantages:

• Increasing the complexity of the class
• may lead to hard-to-find errors ifinit () Method not called in all constructors

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