实例 Java 修饰符 abstract

// abstract class

abstract class Main {

  public String fname = "John";

  public String lname = "Doe";

  public String email = "john@doe.com";

  public int age = 24;

  public abstract void study(); // abstract method 

}

​

// Subclass (inherit from Person)

class Student extends Main {

  public int graduationYear = 2018;

  public void study() {

    System.out.println("Studying all day long");

  }

}

​

class Second {

  public static void main(String[] args) {

    // create an object of the Student class (which inherits attributes and methods from Main)

    Student myObj = new Student(); 

    System.out.println("Name: " + myObj.fname + " " + myObj.lname);

    System.out.println("Email: " + myObj.email);

    System.out.println("Age: " + myObj.age);

    System.out.println("Graduation Year: " + myObj.graduationYear);

    myObj.study(); // call abstract method

  }

}

​