Should I use string.isEmpty() or “”.equals(string)?

Question

The title basically says it all. I'm usually testing this alongside a string == null, so I'm not really concerned about a null-safe test. Which should I use?

String s = /* whatever */;

...

if (s == null || "".equals(s))

{

    // handle some edge case here

}

or

if (s == null || s.isEmpty())

{

    // handle some edge case here

}

On that note - does isEmpty() even do anything other than return this.equals(""); or return this.length() == 0;?

Answer 1

The main benefit of "".equals(s) is you don't need the null check (equals will check its argument and return false if it's null), which you seem to not care about. If you're not worried about s being null (or are otherwise checking for it), I would definitely use s.isEmpty(); it shows exactly what you're checking, you care whether or not s is empty, not whether it equals the empty string