What are extendsT and superT in Java
This article mainly explains "what are extendsT and superT in Java". Interested friends might as well take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "what are extendsT and superT in Java?"
? Wildcard type
The difference between a type parameter and a type parameter is that all T represents the same type for the compiler. For example, in the following generic method, all three T refer to the same type, either String or Integer.
Public List fill (T... T)
But wildcards do not have this constraint, List simply means: there is something in the collection, I don't know what it is.
So that's the mistake here, List.
