The meaning of public in java

The public access modifier in Java allows a class, method, or field to be accessed from anywhere, including the class, subclasses, and different packages. It indicates that the element has the most permissive access level, which can improve code reusability and extensibility.

The meaning of public in Java

In Java, public is an access modifier used to control classes , method or field visibility. It means that the element can be accessed from anywhere, including within the class, subclasses, and different packages.

Access Levels

There are four access levels in Java, arranged from loosest to strictest as follows:

• public
• protected
• default (package level)
• private

The role of public

Declare a Elements that are public have the following effects:

• Class: public classes can be accessed and instantiated in any package.
• Methods: public methods can be called in any class, even if the class is not a subclass or belongs to a different package.
• Fields: public fields can be accessed in any class, including subclasses and classes belonging to different packages.

Example

<code class="java">// 公有类
public class Person {

    // 公有字段
    public String name;

    // 公有方法
    public void sayHello() {
        System.out.println("Hello, my name is " + name);
    }
}</code>

In this example, the Person class, name field and sayHello() method are all public and therefore can be accessed in any class and use.

Importance

The public access modifier is important for creating components that are accessible in different parts of the application, including different packages. It improves code reusability and extensibility.

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