what is protected keyword in the classes?

Answer 1

any protected attribute can be accessed by the class itself and any class that inherit that class
but cannot be accessed otherwise

Answer 2

protected method or attribute can only be accessed withing parent class or subclass e.g let's say you have
Class Foo {
protected String name = "some text";

public String void myFunc(){
//code here
}
}

class Bar extends Foo{

public static void main(String args[]){
System.out.println(new Foo().name);
}
}
//Output: some text

but if you try to access name attribute in class that is not a subclass of Foo you will get error.

Answer 3

thank you all my friends!