子类中的Java构造函数错误

Question

class Person 
{
    String name = "No name";

    public Person(String nm)
    {
        name = nm;
    }
}
class Employee1 extends Person
{
    String empID ="0000";
    public Employee1(String id)
    {                            // Line 1
        empID = id;
    }
}
public class EmployeeTest 
   {
       public static void main(String[] args) {
           Employee1 e = new Employee1("4321");
           Person p = new Person("Hello");
           System.out.println(e.empID);
       }
   }

我得到编译错误说 constructor Person in class Person cannot be applied to given types; required String found no arguments 但是当我在 main 方法中创建新对象时，我正在为父类和子类传递参数。无法弄清楚为什么编译错误？

Answer 1

您需要正确地创建父类，将名称作为Person 构造函数的要求传递给它:

public Employee1(String id) {
    super("person name");   // create the parent
    empID = id;
}

或者可能是这样的:

public Employee1(String id, String name) {
    super(name);   // create the parent
    empID = id;
}

public static void main(String[] args) {
    Employee1 e = new Employee1("4321", "Hello");
    // ...
}