Java 継承（inheritance）

１，継承（inheritance）とは

あるクラスが他のクラスから属性（attributes）やメソッド（methods）を取得するプロセスです

２，ソースコード

Main.java

public class Main {

    public static void main(String[] args) {

        // inheritance = the process where one class acquires,
        //               the attrivutes and methods of another.

        Car car = new Car();
        car.go();

        Bicycle bike = new Bicycle();
        bike.stop();

        System.out.println(car.speed);
        System.out.println(bike.speed);

        System.out.println(car.doors);
        System.out.println(bike.pedals);

    }

}

継承元👇

Vehicle.java

public class Vehicle {

    double speed;

    void go() {
        System.out.println("This vehicle is moming");
    }

    void stop() {
        System.out.println("This vehicle is stopped");
    }

}

クラスからクラスへ継承する場合、”子クラス　extends　親クラス” と表記します👇

Car.java

public class Car extends Vehicle {

    int wheels = 4;
    int doors = 4;

}

Bicycle.java

public class Bicycle extends Vehicle {

    int wheels = 2;
    int pedals = 2;

}