JavaScript is a very flexible language, we can write JavaScript code freely with various styles, different kinds of codes will have different execution efficiency. Here we summarize some tips we get from our development.Efficiency of JavaScript itselfJavaScript has execution context chain, closures, prototype inheritance, eval etc. It brings us some magic features, but it also introduces the performance issue, if we don't use them properly, it will affect the codes execution efficiency.1. Global variableWe may use global variables such as window,document and some custom global variables while ...