Thread: protected Access Specifier

I suggest you read about the protected keyword and see what it means to be protected. While you are there check out the other options. It will all be clear if you read that one page..

I think helloworld922 misunderstood. Perhaps I misunderstood. Maybe this will clear it up:

public class A {
 
	protected String name;
	private String surname;
}
 
 
public class B extends A {
 
}
 
 
public class X {
 
	public static void main(String args[]) {
		B object = new B();
 
                //protected
		object.name = "Hello";
		System.out.println(object.name);
 
                //private
		//object.surname = "World";  //Will not work!
                //System.out.println(object.surname);  //Will not work!
	}
}

The object.name will work as I believe you suggested in your first post. Now that is to assume you have the classes in the same package. Read this page.

thanks .. for explanation .
it means protected members are visible to the main . as long as it is the same package..

Originally Posted by spark

...it means protected members are visible to the main...

Protected would not just be visible to main...
Protected is visible to the entire class where it is declared. It is visible to the entire class of any class that extends the original class. It is visible to the entire class of any class in the same package the original class is in. Private would be the keyword that would offer the "protection" I think you expected from "protected String name;" in your original post.

thanks man.

Originally Posted by helloworld922

Minor correction: protected is not visible to any other class in the same package. It is only visible to that class and classes which extend that class. There is another visibility mechanism which allows this behavior (the 'default' visibility). This behavior is used when no modifier is used.

package test;
public class A
{
    protected String name;
    String address;
}

package test;
 
public class Main
{
    public static void main(String[] args)
    {
        A a = new A();
        a.address = "123 fake street"; // ok since they're in the same package
        a.name = "Spock"; // compile error
    }
}

I disagree completely. Your code compiles as is.
...and with an output:

package test;
 
public class A
{
    protected String names;
    String addresses;
}

package test;
 
public class Main
{
    public static void main(String[] args)
    {
        A a = new A();
        a.addresses = "123 fake street"; // ok since they're in the same package
        a.names = "Spock"; // NOT a compile error
 
        System.out.println(a.addresses + " " + a.names);
    }
}

Output:

123 fake street Spock

Controlling Access to Members of a Class (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

(In horrible detail the JLS has a section on Access Control)

Originally Posted by pbrockway2

Controlling Access to Members of a Class (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

(In horrible detail the JLS has a section on Access Control)

Ya that is the same link I posted which states:

The protected modifier specifies that the member can only be accessed within its own package (as with package-private) and, in addition, by a subclass of its class in another package.

Sorry, I didn't see the link.

in the same package it is accessible

thanks all of you .