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NullPointerException

Joel Christophel
Ranch Hand

Joined: Apr 20, 2011
Posts: 237
    
    1





It compiles, but I get a NullPointerException, Why in the world is this happening?
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39478
    
  28
Very common error. You create an array, which contains 300 nulls, until you assign something to them. Maybe you can iterate through the array and assign them all like this
myArray[i] = new Foo(...);


Remember: a newly-created array is implicitly full of nulls, until you put something in their place.
Claudiu Chelemen
Ranch Hand

Joined: Mar 25, 2011
Posts: 71

It's because you declared an array of elements, but no elements are inside it. Afterwards, you're trying to call the set methods on two objects that aren't there...

Claudiu
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: NullPointerException