Switching order for equals operator

[Brian Schotky]

Hi all,

I've seen in several places that a way to avoid null pointer exceptions is to switch the order of the equals operator. For example, using

  
"Jack".equals(dog);

Instead of:

    
dog.equals("Jack");

Although this seems like a good idea, doesn't this make it harder to debug down the line if you run into problems? Isn't is basically hiding the fact that you have a NPE where you shouldn't?

Just curious what your thoughts were.

Thanks!

[Rob Spoor]

In my opinion, you should only write this code if otherwise you would have written

if (dog != null && dog.equals("Jack"))

In other words, if you already intended to have the null check in place.

[Campbell Ritchie]

If there is any chance of "dog" being null, then dog.equals("Fido") will throw an Exception and "Fido".equals(dog) will not throw an Exception.

[Patricia Samuel]

General Practice is this only that Rob has suggested.

       1. if (dog != null && dog.equals("Jack"))