Java笔记2--继承

猫和狗的继承(jdk-1.8)

首先创建猫和狗的类,声明变量,找到共同点(姓名,年龄),将共同点创建为父类:Animal.java

package EXTEND.Cats_and_Dogs;

public class Animal {
    private String name;
    private String age;

    public Animal() {
    }

    public Animal(String name, String age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

然后继续修改猫、狗类

cat.java

package EXTEND.Cats_and_Dogs;

public class Cat extends Animal{
    public Cat() {
    }

    public Cat(String name, String age) {
        super(name, age);
    }

    public void catch_mouse() {
        System.out.println("Cat can catch the mouse");
    }
}

dog.java

package EXTEND.Cats_and_Dogs;

public class Dog extends Animal{
    public Dog() {
    }

    public Dog(String name, String age) {
        super(name, age);
    }

    public void protect_home() {
        System.out.println("Dog can protect the door");
    }
}

最后进行测试(需要在相同包下测试)

package EXTEND.Cats_and_Dogs;

public class demo {
    public static void main(String[] args) {
        Cat c1 = new Cat("小黄", "7");
        Cat c2 = new Cat("Tom", "5");
        System.out.println(c1.getName() + ", " + c1.getAge());
        System.out.println(c2.getName() + ", " + c2.getAge());
        c1.catch_mouse();
        c2.catch_mouse();
    }
}

注意:

cat和dog类中,先构造一个无参函数,再构造带参函数。

带参函数需要使用super()来访问父类的变量。

main中调用时直接传递参数即可。

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