子类继承父类时JVM报出Error：Implicit super constructor People() is undefined for default constructor. Must define an explicit constructor

当子类继承父类的时候，若父类没有定义带参的构造方法，则子类可以继承父类的默认构造方法

当父类中定义了带参的构造方法，子类必须显式的调用父类的构造方法

若此时，子类还想调用父类的默认构造方法，必须在父类中明确声明默认的构造方法

 package com.gaohui; public class Test {
     public static void main(String [] args){
         Man man = new Man(24,"Tom");
         man.eat();
         man.eat("Tom");
         man.Exercise();
         Woman woman = new Woman();     } } class People{
     private int age;
     private String name;
     private String sex;     public People(){
         //如果父类没有声明默认的构造方法，子类继承时必须显式调用父类定义的构造方法
     }     public People(int age, String name){
         System.out.println("构造方法一执行了！");
     }     public void eat(){
         System.out.println("People need to eat!");
     }     public void eat(String name){
         System.out.println(name+" needs to eat!");
     } } class Man extends People{
     public  Man (int age, String name){//由于父类的构造方法是有参的，必须显式调用父类的方法
         super(age,name);
     }     public void Exercise(){
         System.out.println("I love doing exercise!");
     }
 } class Woman extends People{ }