The relationship between Java function access modifiers and inheritance

Access permission modifiers determine the access scope of classes, methods and fields, and play an important role in inheritance: public: Allow access to all classes and subclasses. protected: allows access by classes and their subclasses in the same package. default: Allow access to classes within the same package. private: Allows access only to the class itself that defines the modifier. A subclass cannot access the members of the parent class using the private modifier, but can change the value of the parent class member with the protected modifier. If you do not specify an access modifier, the member will default to default (package scope).

The relationship between access modifiers of Java functions and inheritance

The access modifiers in Java determine classes and methods and field access scope play an important role in inheritance. The following is the relationship between access modifiers and inheritance:

• public: Grants access to all classes and subclasses.
• protected: Grants access to classes and their subclasses in the same package.
• default (package scope): Grants access to classes in the same package.
• private: Grants access only to the class itself in which this modifier is defined.

Practical case:

Suppose we have a parent class Animal and a subclass Dog:

public class Animal {
    protected String name;
    public void eat() {
        System.out.println("Eating...");
    }
}

public class Dog extends Animal {
    public void bark() {
        System.out.println("Barking!");
    }
}

In the above code:

• Animal’s name field uses the protected modifier, so ## The #Dog class has access to it. The eat()
method of
• Animal uses the public modifier, so it can be called by both the Dog class and other classes it.
• Dog's bark() method uses the public modifier, so any class can call it.

Note:

Subclasses cannot access members of the parent class using the
• private modifier.
Subclasses can change the value of parent class members with the
• protected modifier.
If no access modifier is specified, the member will default to
• default (package scope).

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