class Person{ String name; int age; Person(){ System.out.println("Person无参数构造函数"); } Person(String name,int age){ this.name = name; this.age = age; System.out.println("Person有参数构造函数"); } void eat(){ System.out.println("吃饭"); } }
class Student extends Person{ String grade; Student(){ System.out.println("Student的无参数构造函数"); } Student(String name,int age,String grade){ super(name,age); this.grade = grade; } }
class Test{ public static void main(String[] args){ Student stu = new Student("haha",6,"xueqianban"); System.out.println("name:"+stu.name+"\n"+"age:"+stu.age+"\n"+"grade:"+stu.grade); } }
子类的构造函数中,编译器会默认的加一个super()父类构造函数。