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meaning of "?" in list

Tanu Gulati
Ranch Hand

Joined: Oct 06, 2008
Posts: 113

as we know
List <Integer> list= new ArrayList<Integer>();
can contain only a list of Integers.

then what is the meaning and use of
List <?> list= new ArrayList<Integer>();
what is the use of "?" symbol in this?

Tanu Gulati
rakesh sugirtharaj
Ranch Hand

Joined: Dec 16, 2007
Posts: 151
It means a list of <<Anything>>. It is called as a wild card. The super class to all Generic collections is not Collection<Object> but a Collection<?>.May be this link could help you understand better.

I agree. Here's the link: http://aspose.com/file-tools
subject: meaning of "?" in list
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