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If you always do it, then the chances of not doing it when it is needed is removed. It removes one more decision to make when writing code.

NullPointerException is a java class that is documented in the API doc. Open the API doc page at: Java Platform SE 7
find NullPointerException in the lower left frame, click on the link and get...

null is a value that object reference variables can have. Since a String class instance is an object, any variable that is a reference to a String can have a null value.

The compiler wants local...