Question

I’ve been taking a look at some GWT code written by various people and there are different ways of comparing strings. I’m curious if this is just a style choice, or if one is more optimized than another:

"".equals(myString);

myString.equals("");

myString.isEmpty();

Is there a difference?

Answer 1

"".equals(myString);

will not throw a NullPointerException if myString is null. That is why a lot of developers use this form.

myString.isEmpty();

is the best way if myString is never null, because it explains what is going on. The compiler may optimize this or myString.equals(""), so it is more of a style choice. isEmpty() shows your intent better than equals(""), so it is generally preferred.