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Should the Singleton instance be a final variable?

Eric Kizaki
Greenhorn

Joined: Jan 21, 2011
Posts: 12

I am doing coding exercises on Bert Bates's OCP Java SE 6 Programmer Practice Exams book. One of the questions is to write a singleton class (pg. 150).
Should the singleton instance be a final variable?



OCPJP 6
Paul Clapham
Bartender

Joined: Oct 14, 2005
Posts: 18643
    
    8

Did you try changing the declaration for that variable to include "final"? What happened then?
Eric Kizaki
Greenhorn

Joined: Jan 21, 2011
Posts: 12

I had to rewrite a lot of it. Now I think it won't be changed.

Javin Paul
Ranch Hand

Joined: Oct 15, 2010
Posts: 281


Hi Dude,

I don't think there is a need to make single instance as final but while writing Singleton class its worth noting to implement double checking of Singleton instance. e..g




Thanks
Javin


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Vijitha Kumara
Bartender

Joined: Mar 24, 2008
Posts: 3837

And welcome to CodeRanch, Eric Kizaki


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