JavaScript

One of the management of asynchronous programming is error handling. In synchronous code, it is easy to handle all errors at once by wrapping a piece of code with a try statement block.try{ f(); g(); h();} catch(e){ //这里用来下得出现的错误}Try

Global variables should be retained by objects that have system-wide dependencies, and their naming should avoid ambiguity and minimize the risk of naming conflicts.In practice, this means that you should avoid creating global objects unless they

The code is as follows: App.use (function (req, res, next) {var err = new Error (' not Found '); Err.status = 404; Next (ERR); }); App is object, use is method, method parameter is aanonymous functions with parameters, the function body is given

JavaScript closures have two uses: one is to access variables inside the function, and the other is to keep the value of the variable within scope. The function is the only scoped object in JavaScript, so the closure of JavaScript depends on the

In Java, the trim () function represents the removal of the front and back spaces of a string, but there is no trim () function in JavaScript, so you need to override this function if you want to use it. Specific as follows:function Trim (str) {

EffectHtml:DOCTYPE HTML>HTML> Head> MetaCharSet= "UTF-8"> title>title> Linkrel= "stylesheet"type= "Text/css"href= "Css/image.css"/> Scripttype= "Text/javascript"src= "Js/jquery-2.1.0.js" >Script> Scripttype=

1, JS has several data types?JS consists of 5 simple data types: Undefined, Null, Boolean, number, String, and a complex data type: object.2, the role of typeof?If we want to know which data type a variable belongs to, then you can use the TypeOf

If you are used to understanding and analyzing problems from the perspective of "class", then the inheritance implementation based on constructors is more suitable for you, and the 01~06 method is based on constructors.If you are only dealing with

These two years of offline browsing technology is becoming more and more popular, the most common is the HTML5 mobile application, there are many common web apps also use these technologies. However, the advent of new technologies can sometimes lead

4.1.4 Detection TypeAlthough TypeOf is the right hand when detecting a base data type, we do not want to know if a value is an object while detecting the value of a reference type, but want to know what type of object it is. The instanceof operator

In-depth analysis of the plus signs and exclamation points before JavaScript Functions, analysis of javascript + Function (){}(); The plus sign can also be replaced !,~ And other unary operators, the effect is equivalent: (Function () {console.

A very good FLASH plug-in, a very good flash plug-in Paste a piece of code to see the effect:   Codebase = "http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0"Width = "160" height = "70" id = "honehoneclock" align

Understanding about absolute positioning: absolute positioning understanding about absolute positioning This is a small box

Css layout: negative margin and Other implementations; css layout: margin I believe that you have encountered this kind of requirement in project development. One row is placed with X (X> 1) blocks and the spacing between adjacent blocks is the same.

Fully parse the "&" and "|" operators in JavaScript (Summary) and fully parse JavaScript 1. | (logical or ), Literally, false is returned only when both the front and back are false. Otherwise, true is returned. alert(true||false); //

CSS Pseudo-classes, csspseudo-classes Here is a golden rule: The pseudo-class effect can be achieved by adding an actual class; the pseudo-element effect can be achieved by adding an actual element.   Part 1: Pseudo-classes   I. Link System (This

CSS layout-center, css layout Reference Article 1. CSS layout odd sex techniques-various Center 2. http://www.imooc.com/article/2235 1. Horizontally centered text-align: centerHorizontally center the image, button, text, and other in-row elements

The reason why jQuery's Each performance is much slower than JS's native for loop performance is that jqueryeachjs In fact, looking at the jQuery source code, we found that the each code is very simple, but why is the performance dozens of times

A simple and easy-to-understand pop-up box for mobile terminals First, let us show you that if you feel pretty good, please refer to the implementation code. The key code is as follows: Function tishi (content, url) {var html = ' '; $

A Simple Method for JS to select DOM elements. js selects dom From the JavaScript authoritative guide (the ultimate way for jQuery to find elements based on the style selector is to first use getElementsByTagName (*) to get all DOM elements, and