Java,super用法实例

class  Father{
String name;
int age;
public  Father(){
name="Tom";
age=10;
}
}
class Son  extends Father{
public Son(){
//-----1
//System.out.print(name+","+age);///输出：Tom,10
//-----2
super(); //// Father()是无参构造函数，写不写	super();都一样
System.out.print(name+","+age);///输出：Tom,10
}
}
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Son son  =new Son();
}
}

class Father {
String name;
int age;
public Father(String name, int age) {
this.name = name;
this.age = age;
}
}
class Son extends Father {
public Son() {
// -----1错误， 调用父类无参数的构造函数，但没有，会报错
// super(); //// FFF
// System.out.print(name);///

// //-----2正确
super("Dave", 2);// /TTT 显式调用父类的构造函数
System.out.println(getClass() + "," + name + "," + age);// 输出：class	Son,Dave,2
System.out.print(getClass() + "," + this.name + "," + this.age);// 输出：class	Son,Dave,2
// //Son继承Father后，也继承了name和age的变量值

// -----3 错误 默认调用父类无参数的构造函数，但没有，会报错
// System.out.println(getClass()+","+name+","+age);
// System.out.print(getClass()+","+this.name+","+this.age);
//提示： Implicit super constructor Father() is undefined. Must explicitly invoke another constructor
// /必须要定义其他的父类构造函数
}
}
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Son son = new Son();
}
}