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Khalid Mock - Hashcode Q

 
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Given the following class, which are correct implementations of the hashCode() method?


Select any 3

1) return 0;
2) return a;
3) return a+b;
4) return a-b;
5) return a^b;
 
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Do you understand the "hashCode contract" (as described in the API for the hashCode method in the Object class)?
 
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According to the contract :
if obja.equals(objb) is true iff if hashcode(obja)==hashcode(objb)
but viceversa may not be true.

so here the answers are


return 0
return a+b
return a^b



try to find out why this so from the code ..you will find out these are
the correct ones ....
 
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Have a look at this and see if it is of any help -
http://www.geocities.com/technofundo/tech/java/equalhash.html

HTH,
- Manish
 
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