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AutoBoxing Integer to int conversion

 
Greenhorn
Posts: 3
Mac OS X Java Ubuntu
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int a = (Integer) null;

throws a null pointer exception. Is this documented in javadoc? also if any one could point out why is it not assigned 0 which will be the default for an int.
 
Bartender
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Hi and welcome to the Javaranch.

What happens is that you have an Integer reference with you want to convert into an int value. This happens by calling the intValue() method on the Integer reference.
But because the Integer reference is null it results in a NullPointerException.
 
Marshal
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It's in the Java™ Language Specification . Look what it says about null on that page.
 
Java Cowboy
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To show in code what Wouter explained, your line of code is the same as this:

 
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