IE JScript 效能校調原則

IE Blog上列舉了許多針對JScript效能校調的指南。雖然有些看起來似乎沒有順應Modern JavaScript的Programming Model。Anyway, 開發JScript應用程式的人還是可以看看自己的程式碼還可以擠出多少效能。

1. Symbolic Look-up Recommendations
• Evaluating Local Variables
• Cache Variables Whenever Possible
• Cache Function Pointers at all costs
• Avoid Using the ‘with’ Keyword
2. JScript Code Inefficiencies
• Optimize String Manipulations by Avoiding Intermediate Results
• Running Code Using the ‘eval’ Statement is Expensive
• Requirements of Eval for JSON Expressions
• Switch Blocks are Linear Evaluation Tables
• Avoid Closures if Possible
• Don’t use Property Accessor Functions

如果你想要直接Hack JScript Garbage Collection的機制，這邊請吧。

 

Reference:

IE + JavaScript Performance Recommendations - Part 1
http://blogs.msdn.com/ie/archive/2006/08/28/728654.aspx

IE+JavaScript Performance Recommendations Part 2: JavaScript Code Inefficiencies
http://blogs.msdn.com/ie/archive/2006/11/16/ie-javascript-performance-recommendations-part-2-javascript-code-inefficiencies.aspx

IE+JScript Performance Recommendations Part 3: JavaScript Code Inefficiencies
http://blogs.msdn.com/ie/archive/2007/01/04/ie-jscript-performance-recommendations-part-3-javascript-code-inefficiencies.aspx

You may experience slow performance when you view a Web page that uses JScript in Internet Explorer 6
http://support.microsoft.com/?scid=kb%3Ben-us%3B919237&x=9&y=9