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Java question mark with super in method call query

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  • 05-02-2013 7:10pm
    #1
    veryangryman
    Registered Users Posts: 5,558 ✭✭✭


    See attachment

    Can you explain what is occurring there? A quick google does nothing for me, thanks if you can help


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    #2
    Colonel Panic
    Registered Users Posts: 2,022 ✭✭✭Colonel Panic


    Java generics seem so lame. I just put List<? super String> into Google btw...

    Basically, it means the list can hold any class that's a superclass of String, including String itself.


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    #3
    GreeBo
    Registered Users Posts: 27,161 ✭✭✭✭GreeBo


    Colonel Panic wrote: »
    Java generics seem so lame. I just put List<? super String> into Google btw...

    Basically, it means the list can only hold any class that's a superclass of String, including String itself.

    FYP.
    OP its compile time type checking, prevents you having to check the object type during runtime.
    e.g.
    if( obj instanceof String) {
String str = (String)obj;
//do something
else {
panic
}


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