Passing array to function with generic data type argument

Question

Why does this work

public E a;
public MySortedArray(E asdf){
    a = asdf;
}

and this doesn't?

public E[] a;
public MySortedArray(E[] asdf){
    a = asdf;
}

How can I achieve the second when let's say I do

    MySortedArray<Integer> test = new MySortedArray<>(integersArray);

See [Restrictions on Generics](https://docs.oracle.com/javase/tutorial/java/generics/restrictions.html) in the Java Tutorial. For the second, you should use `List` instead of `E[]` and use the `List` API instead of array subscripting. — Ted Hopp, Nov 12 '14 at 19:38
@TedHopp I don't think that this involves the creation of a generic array as in your "duplicate of"; just the passing of an array to a generic class. — rgettman, Nov 12 '14 at 19:40
@TedHopp I thought as well, but we are restricted from doing so. — MayTheSchwartzBeWithYou, Nov 12 '14 at 19:42

score 2 · Accepted Answer · answered Nov 12 '14 at 19:44

2

Java does support boxing int to Integer, but not boxing arrays of those numeric types, e.g. it won't box int[] to Integer[].

You must convert the int[] to an Integer[] yourself before passing it to your MySortedArray<Integer> instance.

answered Nov 12 '14 at 19:44

rgettman

thanks! I still need to practice on Generics, as I always avoided them even in advanced projects. – MayTheSchwartzBeWithYou Nov 12 '14 at 19:52
1

May the `? extends Force` be with you. – rgettman Nov 12 '14 at 20:00

1 Answers1