This is a note about Javascript Performance, by reading the amazing book by , which helps developers to identify problem and providing better solution, to improve execution time, downloading, interaction with the DOM, page life cycle, and more. High Performance JavaScript Nicholas C. Zakas Data Access Concepts such as the and can affect your overall script performance. scope chain prototype chain DOM Scripting DOM interaction is slower than other parts of JavaScript, how repaint and reflow can slow down your code. Algorithms and Flow Control Loops and recursion can work against you when it comes to runtime performance. Strings and Regular Expressions Poor string-handling performance in browsers, work around methods is explained Responsive Interfaces User experience, several techniques is discussed to ensure that the user interface remains responsive at all times. Ajax Different data formats can affect Ajax performance and why isn’t always the best choice. XMLHttpRequest Remark Evolution of JS JavaScript was first introduced as part of in Netscape Navigator 1996 Google introduced their brand-new browser called in Chrome 2008. The V8 JavaScript engine is a , which produces from JavaScript code and then executes it. just-in-time (JIT) machine code Things affect JS Delays caused by network latency and operations, affecting the appearance on browser Simple optimizations such as , , and are easily optimized in compilers, it solves only part of the performance problem. function inlining code folding string concatenation algorithms Original goal of JS JS is originally designed for form validation JS is originally designed for functionality directly in the page Reference — http://shop.oreilly.com/product/9780596802806.do
![[Note] 19 Coding Rules that every coder must know](https://hackernoon.imgix.net/hn-images/1*LwkasdSEFs7rhv21ayrfxA.png?auto=format&fit=max&w=3840)
