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Help needed!


Joined: Nov 08, 2004
Posts: 5
In Java, a method call on an object such as x.f() is resolved, when the program executes, not when it is compiled, in order to support polymorphism. Name two situations, where The Java Compiler can determine the exact method to be called before the program executes..?

Please help, so far I am thinking about, if it can have anything to do with casts?
David Harkness
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Joined: Aug 07, 2003
Posts: 1646
If f() is a static method, which f() is called is determined by the compiler based on x's declared type.

As for a second case, if f() is declared final in the class that x is declared to be. Heh, that might take an example.I would expect that line 2 will be compiled as a polymorphic lookup of f() since it could be A.f() or B.f() based on the instance x references at runtime.

However, line 5 should be compiled to directly call B.f() since that's the only option for a C (or any subclass of it).

Of course, IANAJVMA, so YMMV.

Joined: Nov 08, 2004
Posts: 5
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