Java基础之super关键字浅析

public class Parent {
    public String name = "小头爸爸";
    public boolean hasMoney = false;
 
    public void sleeping(){
        System.out.println("爸爸已经睡了");
    }
 
    public void working(){
        System.out.println("爸爸正在工作。。。");
    }
}
 
public class Child extends Parent {
 
    public String name = "大头儿子";
 
    /**
     * 当子类和父类有属性重名时，需要super才能调用到父类的属性，
     * 直接调用会调用到子类的属性
     * 如果不重名，可直接调用且调用的是父类的属性
     */
    private void testParam(){
        System.out.println("爸爸的名字叫" + super.name);
        System.out.println("孩子的名字是" + name);
        System.out.println("爸爸是否有有钱：" + hasMoney);
    }
 
    /**
     * 方法和上面的属性结果一样
     */
    public void testMethod(){
        sleeping();
        super.sleeping();
        super.working();
    }
 
    public void sleeping(){
        System.out.println("儿子已经睡了");
    }
 
    public static void main(String[] args) {
        Child child = new Child();
        child.testParam();
        child.testMethod();
    }
}

public class Parent {
    ...
    public Parent() {
    }
    ...
}
 
public class Child extends Parent {
    ...
    public Child() {
    }
    ...
}

public class Parent {
    public String name = "小头爸爸";
    public Parent(int age) {
    }
 
    public void sleeping(){
        System.out.println("爸爸已经睡了");
    }
}
 
public class Child extends Parent {
    public String name = "大头儿子";
    public Child() {//如果没有super来初始化父类，同样也会报错
//        super();//编译期报错,因为父类并没有无参构造函数
        super(15);//正确打开方式
    }
 
    private void printParentName(){
        System.out.println("爸爸的名字叫" + super.name);
    }
 
    private void parentStatus(){
        super.sleeping();
    }
}

class Person {
    int id;
    String name;

    Person(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

class Emp extends Person {
    float salary;

    Emp(int id, String name, float salary) {
        super(id, name);// reusing parent constructor
        this.salary = salary;
    }

    void display() {
        System.out.println(id + " " + name + " " + salary);
    }
}

class TestSuper5 {
    public static void main(String[] args) {
        Emp e1 = new Emp(1, "ankit", 45000f);
        e1.display();
    }
}