小编Wou*_*out的帖子

我最近开始编程,我忙于继承,多态和覆盖.现在我刚刚制作了这个程序,由于某些原因它不起作用.编译器强调"= new Arraylist();但我不知道为什么.

代码如下:

超级:人

public class Person {
private String firstName;
private String lastName;

public Person(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
}

public void print() {
    System.out.println("\t" + firstName + " " + lastName);
}
}

子类:老师

public class Teacher extends Person {
public Teacher(String firstName, String lastName) {
    super(firstName, lastName);
}

public void print() {
    System.out.println("Professor Details: ");
    super.print();
}

}

子类学生:

public class Student extends Person {
private int graduationYear;
private double …