Create your own version of Java’s StringBuilder:
var StringBuilder = function (str) {
var _stack = str ? [str] : []; // str == initial string to start, if any
// append can take one or more strings as arguments
this.append = function () {
_stack.push.apply(_stack, arguments);
return this;
}
this.toString = function (separator) {
return _stack.join(separator || '');
}
}This routine runs up to 8x faster in IE6 than normal string concatenation using the + and += operators! In IE7, I’ve clocked a 4x improvement.
Firefox 3.0 gets about a 20% speed boost. Safari 4 and Chrome get less than a 10% speed boost.
It would be an easy exercise to modify the StringBuilder class’ append method and constructor to take an existing StringBuilder object instead of a string.
Javascript, performance
The arguments property of the Function object looks a lot like an array, but it’s really not. We say it’s array-like since it has a length property and properties whose names are whole numbers.
Similary, DOM properties, such as Element.childNodes, return a NodeList, which is also array-like.
If you’ve ever been frustrated that you can’t use array methods on these array-like collections, then the following function is your new friend:
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Javascript, performance
If you’ve logged into Facebook lately, you couldn’t have missed the new design. This design brings some much needed features. I especially appreciate the ability to filter my News Feed by friend group. Since I already keep my friends in separate groups (a painstaking process), this was a freebie for me.
But overall, Facebook disappoints for several reasons.
Non-programming
Wow. It’s been almost 2 years since I’ve finished a technical blog post! I’ve started plenty, but have just never quite finished any. I figure it’s either because I try to tackle too much in a single post and/or because I am way too picky about the topic. Anyways, here’s a new blog post to prove I didn’t actually fall off the face of the Earth!
In my previous post, I laid out the basic Javascript inheritance mechanism, prototype chaining. In this post, I’ll elaborate on it a bit more by showing how I took this basic concept and created something workable for some very bright, but prototype-phobic programmers: Oracle Life Sciences division’s Java developers! (Java and Javascript couldn’t be more different in almost every regard, especially concerning inheritance.)
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Inheritance, Javascript, prototype.js
Most of the Javascript I write is object-oriented. While deciding what I would write about in my first posts, I realized that I would probably have to review Javascript OO techniques first. Any source code I included would be unintelligible to the uninitiated. In this post — and in the subsequent ones — I will review the Javascript inheritance techniques I use and explain why and when I use them.
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Inheritance, Javascript
