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Generic Declaration

 
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Dear All,

please find the one below from devaka coorey simulator



I have compiled above code to see what happened. I don't understand compiler error that said

type parameter K is not within its bound and type parameter ? super V is not within its bound


what is error exactly mean and I'm not clear enough how to deal with question like this.

really appreciate for any kind help. thank you.
 
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what is error exactly mean and I'm not clear enough how to deal with question like this.



This option...



is just too weird. Hopefully, this will never be encountered in real code. My main issue is this generic method declares a generic type K, but the method is in a class that also has a generic type K. It's just too confusing to figure out which K is which...

But to answer your question...

This generic method is defining a new type K (which is unbounded), and then declares a method that takes a Fractal of type K, and returns a Fractal of type K. Unfortunately, Fractual can't take an unbounded type. It can only work with types that extend Number.

This is what the compiler meant by "type parameter K is not within its bound". The unbounded type K can't be used as part of Fractal.

Henry
 
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Henry Wong wrote:My main issue is this generic method declares a generic type K, but the method is in a class that also has a generic type K. It's just too confusing to figure out which K is which...




The Explanation for this question says:

When you have declare a generic type for a method, as same as to the generic type declare for the class, the class-generic-type will be shadowed by the, method's-generic-type. Therefore, for this method, K is just a new generic type.



Hmmm,.... Is this question too much tough for SCJP? Let me know, if it is, I'll remove this question from the next version of ExamLab.

Devaka.
 
Vierda Mila
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Hmmm,.... Is this question too much tough for SCJP?



dear Devaka,

I don't know about others thinks but I have to reschedule my exam after trying your simulator . in another mock I can gained 75%-80% but in yours I never get beyond 55% thats mean I'm fail in exam

but really appreciate for this simulator.it makes me to learn a lot. and thanks for make it free. keep a great job man
 
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