Comments on: String.toCharCode

By: Heironymus P. Organthruster

Heironymus P. Organthruster — Tue, 09 Mar 2010 12:39:54 +0000

all versions of IE 6.x and greater barf at:

String.charCodeAt(str[i]);

whereas

str[i].charCodeAt(0);

seems to keep them happy.

By: Mauvis

Mauvis — Sun, 16 Nov 2008 09:40:31 +0000

I agree that as a general utility function it should return an array for greater control and to do that you would just return work; instead of return work.join(','); However, for the situations I needed it I just needed a string.

By: Erik Vold

Erik Vold — Sun, 16 Nov 2008 05:59:11 +0000

Hey, nice function, but I was thinking, maybe it should return an array, as the input used by fromCharCode is an array.

What do you think?

By: Ten Eyck - Process String

Ten Eyck - Process String — Tue, 28 Oct 2008 04:54:47 +0000

[...] My good friend Mauvis was writing on his blog about to convert a string to comma separated ascii numbers. I commented there about his code. Here’s how I wrote, and also see his original: String.toCharCode(). [...]

By: Mauvis

Mauvis — Mon, 27 Oct 2008 22:35:05 +0000

I profiled it in Firebug and it is indeed 30% faster. :]

By: tksh

tksh — Mon, 27 Oct 2008 22:16:28 +0000

String concatenation is (usually) very heavy in any loop, so as a general rule, you shouldn’t do that. It’s because String is basically immutable, although Firefox and Safari’s implementation of String is very efficient.

By: Mauvis

Mauvis — Mon, 27 Oct 2008 19:10:44 +0000

Takashi king of efficiency!

I like your changes and will add your version beneath mine. I completely agree about not using for in. This was quick and dirty and admitting I wasn’t thinking (also I generally steer clear of adding prototypes to native objects – I only run this in Firebug when I need it.)

I also like your use of join instead of all the string logic.

Thanks!

By: tksh

tksh — Mon, 27 Oct 2008 17:59:00 +0000

I suppose there must be the reason to do this way, but the code you wrote would not work when you add other prototype method to String. For example, do like this:

String.prototype.something = ‘foobar’;
‘bob’.toCharCode(); // returns “98,111,98,102″

It’s because you use for…in iteration to run a loop for array. for…in iteration should be very careful. For the future version of JavaScript may be able to access “DontEnum” property, or using hasOwnProperty() . But in this case, it’s easier to do as follows.

String.prototype.toCharCode = function(){
var str = this.split(”);
var len = str.length;
var work = new Array(len);
for (var i = 0; i < len; ++i)
{
work[i] = str[i];
}
return work.join(‘,’);
}