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Index › Programming Questions & Help › Syntax Questions › how to avoid a NullPointerException
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how to avoid a NullPointerException? (Read 590 times)
picturetunes
how to avoid a NullPointerException?
Sep 3rd, 2007, 4:15pm  
hi, i have a little problem with NullPointerExceptionS:

I store a reference of object a as the property refToA of object b. when i call method doSomething of property refToA of object b [b.refToA.doSomething()]i get an NullPointerException if object a doesn't exist. how can i avoid that? can i check if object a exists? in actionscript i.e. i could check if object a exists like this [ if(a.refToA){//exists}] how is this done in java?
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fjen
Re: how to avoid a NullPointerException?
Reply #1 - Sep 3rd, 2007, 5:30pm  
if ( b.refToA != null ) { /* not null */ }
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picturetunes
Re: how to avoid a NullPointerException?
Reply #2 - Sep 4th, 2007, 7:53am  
fjen wrote on Sep 3rd, 2007, 5:30pm:
if ( b.refToA != null ) { /* not null */ }


Ahhhh! makes sense. thanks
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