Question

Is conversion to String in Java using

"" + <int value>

bad practice? Does it have any drawbacks compared to String.valueOf(…)?

Code example:

int i = 25;
return "" + i;

vs:

int i = 25;
return String.valueOf(i);

Update: (from comment)

And what about Integer.toString(int i) compared to String.valueOf(…)?

Answer 1

I would always prefer the String.valueOf version: mostly because it shows what you’re trying to do. The aim isn’t string concatenation – it’s conversion to a string, "the string value of i".

The first form may also be inefficient – depending on whether the compiler spots what you’re doing. If it doesn’t, it may be creating a new StringBuffer or StringBuilder and appending the value, then converting it to a string.

Funnily enough, I have an article about this very topic – written years and years ago; one of the first Java articles on my web site, IIRC.