Wildcard (Java): Difference between revisions

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== Bounded Wildcards ==

A bounded wildcard is one with either an upper or a lower [[Inheritance (object-oriented programming)|inheritance]] constraint. The bounds can be both class and interface types. Upper bounds are expressed using the '''extends''' keyword and lower bounds using the '''super''' kkeywordkeyword. An upper bound on a wildcard must be a subtype of the upper bound on the type parameter it is assigned.

<code>Generic<? '''extends''' SubtypeOfUpperBound> referenceConstrainedFromAbove;</code>