javascriptstringperformancenumbers

What's the best way to convert a number to a string in JavaScript?

What's the "best" way to convert a number to a string (in terms of speed advantage, clarity advantage, memory advantage, etc) ?

Some examples:

  1. String(n)

  2. n.toString()

  3. ""+n

  4. n+""

Solution

  • like this:

    var foo = 45;
var bar = '' + foo;

    Actually, even though I typically do it like this for simple convenience, over 1,000s of iterations it appears for raw speed there is an advantage for .toString()

    See Performance tests here (not by me, but found when I went to write my own): http://jsben.ch/#/ghQYR

    Fastest based on the JSPerf test above: str = num.toString();

    It should be noted that the difference in speed is not overly significant when you consider that it can do the conversion any way 1 Million times in 0.1 seconds.

    Update: The speed seems to differ greatly by browser. In Chrome num + '' seems to be fastest based on this test http://jsben.ch/#/ghQYR

    Update 2: Again based on my test above it should be noted that Firefox 20.0.1 executes the .toString() about 100 times slower than the '' + num sample.