Input:
var i = 10000,
j = 0.1,
k = /[\w]/,
m = new Array(1, 2, 3);
throw 0.1;

Closure:
var i=1E4,j=0.1,k=/[\w]/,m=[1,2,3];throw 0.1;

UglifyJS:
var i=1e4,j=.1,k=/[\w]/,m=new Array(1,2,3);throw.1

Interesting that UglifyJS doesn’t compress the Array declaration, but does compress 2 other statements that Google Closure doesn’t/won’t.

In UglifyJS’s README it states that Google Closure “runs terribly slow”. Why is this an issue? Won’t you only compress when pushing to prod?

Ok browser makers. Let’s start over. I don’t think any site is using the navigator.appVersion anymore so now is as good of time as ever to start fresh. What do you say?

“The null value … can only be assigned by your code.”
From Object-Oriented JavaScript by Stoyan Stefanov

But so will this:
num = 0;
var num = num || 10;
alert(num);

Watch out for the cases where num is “falsey“.

1. I have used <!CDATA[...]> sections when I’m embedding “<” and “>” but I think that’s just because I’ve used XSL before and they have caused problems when performing transformations. But I’ll try to remove it from my HTML as he suggests.

2. If I don’t have a URL to use in the href attribute, I’ll still use “javascript:void(0)” because I really don’t like the hash being added to my URL. Perhaps I should just add some jQuery code:

$(“a[href='#']“).click(function(){return false;});

That’s 49 characters, so I would have to change only 3 links to use the hash instead of “javascript:void(0)” to save space.

I came across a problem in Internet Explorer (it wasn’t a problem with Firefox) when I was trying to compare two strings. To me, one string looked to have an extra space in the front. No problem, I’ll just call the jQuery trim function. Well, that didn’t work. So I used charCodeAt and found it was ASCII character 160. I looked up char code 160 and saw that it is a “Non-breaking space”. You would think that a “space” character would be trimmed. I looked at the jQuery code that does the trimming and the grep pattern uses \s. So, evidently you can’t use \s to catch the “Non-breaking space” in IE. I wonder why no one else has seen this. I wrote up a test page to illustrate this.

To create the non-breaking space, you can use String.fromCharCode(160) or the Unicode representation “\u00A0″. “&#160;” doesn’t seem to work when using regular expressions, although it behaves the same when printed.

function peasant1(a, b) {
  var value = a & 1 ? b : 0;
  while(a > 1) {
    a >>= 1;
    b <<= 1;
    if (a & 1)
      value += b;
  }
  return value;
}

function peasant2(a, b) {
  var value = a & 1 ? b : 0;
  if(a > 1)
    value += peasant2(a >> 1, b << 1);
  return value;
}

function peasant3(a, b) {
  return a > 1 ? (a & 1 ? b : 0) + peasant3(a >> 1, b << 1) : a & 1 ? b : 0;
}

function peasant4(a, b) {
  return a & 1 ? value = a > 1 ? value = b + peasant4(a >> 1, b << 1) : b : value = peasant4(a >> 1, b << 1);
}