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NPE using comparator

 
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I am receiving a NPE while trying to add nodes to a linked list. I am just adding two nodes at the moment to see if it works.


This is the line of the NPE






This is my node class.....Class is marked private as it is an inner class of linked list......

 
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If that line is indeed the root cause of the NPE then comp, which I assume is a reference to the Comparator, must be null, as head can't be null at that point unless you add multi-threading to the mix. That is of course if that line is indeed the root cause of the NPE and it isn't thrown somewhere from inside the compare() method.
 
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Then either the "head" variable is null, or the "comp" variable is null. As far as I can see there, either of those could be the case.
 
Charles Sexton
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Paul Clapham wrote:Then either the "head" variable is null, or the "comp" variable is null. As far as I can see there, either of those could be the case.



comp was null....
 
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