What's the benefit of wildcard generics in Java?

Question

What benefit gives us the second signature method with wildcard <?>?

public static <T> void firstCheckList(List<T> myList, T obj)                
public static <T> void secondCheckList(List<?> myList, T obj)

I don't know about "benefit." Those two lines of code are two totally different things. — markspace, Sep 30 '14 at 15:53
Yes, I know it. The second line gives us more options for type. But I don't know when I should use the second line approach. — barbara, Sep 30 '14 at 15:55
If Im right, it's no sense to use "pure" `>`, but it's very useful in case like this ` extend MyType>`. — barbara, Sep 30 '14 at 16:12

score 1 · Accepted Answer · answered Sep 30 '14 at 16:02

1

The benefit is that in the 2nd option the list members don't need to be the same type as obj

If there is a correlation between myList and obj (type-wise) it is best to use the 1st option, if there isn't use the 2nd option

answered Sep 30 '14 at 16:02

Sigal Shaharabani

1 Answers1