Access Modifiers in Java

    The access modifiers in Java specifies the accessibility or scope of a field, method, constructor, or class. We can change the access level of fields, constructors, methods, and class by applying the access modifier on it.

There are four types of Java access modifiers:

• Private: The access level of a private modifier is only within the class. It cannot be accessed from outside the class.

class A{

private A(){}//private constructor

void msg(){System.out.println("Hello java");}

}

public class Simple{

public static void main(String args[]){

A obj=new A();//Compile Time Error

}

}

• Default: The access level of a default modifier is only within the package. It cannot be accessed from outside the package. If you do not specify any access level, it will be the default.

//save by A.java

package pack;

class A{

void msg(){System.out.println("Hello");}

}

//save by B.java

package mypack;

import pack.*;

class B{

public static void main(String args[]){

A obj = new A();//Compile Time Error

obj.msg();//Compile Time Error

}

}

• Protected: The access level of a protected modifier is within the package and outside the package through child class. If you do not make the child class, it cannot be accessed from outside the package.

//save by A.java

package pack;

public class A{

protected void msg(){System.out.println("Hello");}

}

//save by B.java

package mypack;

import pack.*;

class B extends A{

public static void main(String args[]){

B obj = new B();

obj.msg();

}

}

• Public: The access level of a public modifier is everywhere. It can be accessed from within the class, outside the class, within the package and outside the package.

//save by A.java

package pack;

public class A{

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

}

//save by B.java

package mypack;

import pack.*;

class B{

public static void main(String args[]){

A obj = new A();

obj.msg();

}

}