Access Modifiers in Java

In Java, access modifiers are keywords that are used to control the visibility and accessibility of classes, methods, and variables. Java provides four access modifiers:

1. public – The public access modifier makes a class, method, or variable accessible from anywhere in the program. It is the most permissive access modifier.
2. protected – The protected access modifier makes a class, method, or variable accessible within the same package or in a subclass of the class in a different package.
3. default (no modifier) – If a class, method, or variable has no access modifier, it is considered to have default (package-private) access. This means it is accessible within the same package, but not outside of it.
4. private – The private access modifier makes a class, method, or variable accessible only within the same class.

Here are some examples of how access modifiers can be used in Java:

public class MyClass {
    public int publicVar;
    protected int protectedVar;
    int defaultVar;
    private int privateVar;
    
    public void publicMethod() {
        // Method code here
    }
    
    protected void protectedMethod() {
        // Method code here
    }
    
    void defaultMethod() {
        // Method code here
    }
    
    private void privateMethod() {
        // Method code here
    }
}

In this example, the access modifiers are used to control the visibility of the class and its methods and variables. The “publicVar” and “publicMethod” can be accessed from anywhere in the program, while “protectedVar” and “protectedMethod” can be accessed only within the same package or in a subclass of “MyClass”. “defaultVar” and “defaultMethod” can be accessed only within the same package, and “privateVar” and “privateMethod” can be accessed only within the same class.

Access modifiers are an important tool for controlling the visibility and accessibility of code in Java. By using the appropriate access modifiers, you can create classes, methods, and variables that are both secure and easy to use.