Public access modifier in Java

menu_book

Introduction

The public access modifier allows other parts of your program to use a class, method, or variable freely. It makes things open and easy to reach.

When you want a class to be used by any other class in your program.

When you want a method to be called from anywhere in your code.

When you want a variable to be accessible from any other class.

When creating a main method that the Java runtime needs to access.

When sharing utility methods that many parts of your program need.

regular_expression

Syntax

Java

public class ClassName {
    public int number;
    public void methodName() {
        // code
    }
}

Use public before class, method, or variable to make it accessible everywhere.

Public members can be accessed from any other class in any package.

emoji_objects

Examples

line_end_arrow_notchThis class and its members can be used anywhere in your program.

Java

public class Car {
    public String model;
    public void start() {
        System.out.println("Car started");
    }
}

line_end_arrow_notchThis variable can be accessed from any other class.

Java

public int count = 10;

line_end_arrow_notchThis method can be called from any other class.

Java

public void greet() {
    System.out.println("Hello!");
}

code_blocks

Sample Program

This program uses public members so the main method can create an object and call the printMessage method to show the message.

Java

public class HelloWorld {
    public String message = "Hello, world!";

    public void printMessage() {
        System.out.println(message);
    }

    public static void main(String[] args) {
        HelloWorld hw = new HelloWorld();
        hw.printMessage();
    }
}

emoji_objects

Important Notes

line_end_arrow_notch

Public members are easy to use but be careful not to expose sensitive data.

line_end_arrow_notch

Use public only when you want others to access the member freely.

list_alt_check

Summary

Public means open and accessible from anywhere.

Use it for classes, methods, or variables you want to share freely.

It helps different parts of your program work together easily.