Hi,
I am running through the Java Advanced Topics - Generic Classes and inheritance.
I am using three classes:
- GenericList<T Extends Comparable>
- User (Implements Comparable)
- Instructor (extends user)
I can create an instance of GenericList using User
I get an error when I create a GenericList of Instructor
This doesn’t seem to be a problem in the videos. Below is the code for the classes and a screenshot of the error…
Here is the code:
GenericList:
public class GenericList<T extends Comparable<T>> {
private T[] items;
private int count;
public GenericList() {
items =(T[])new Comparable[10];
count = 0;
}
public void addItem(T item){
items[count++] = item;
}
public T getItem(int pos){
return items[pos - 1];
}
}
User
public class User implements Comparable<User> {
private String email;
public User(String email) {
this.email = email;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Override
public int compareTo(User o) {
return (email.compareTo(o.email));
}
}
Instructor
public class Instructor extends User {
public Instructor(String email){
super(email);
}
}
And here is the error:
