javascript underscore

Basic concepts of JavaScript and basic concepts of javascript I. Case Sensitive All variables, function names, and operators in ECMAScript are case sensitive. For example, the variables test and Test indicate two different variables respectively, Ii. identifier The identifier refers to the name of a variable, function, attribute, or function parameter. One or more characters of the identifier in combin

Learning javascript object-oriented understanding of javascript prototype and prototype chain, javascript object-oriented Let's take a look at a picture and sort it out. I. Basic Concepts　Prototype chain]Each constructor has an object. The prototype object contains a pointer to the constructor, And the instance contains an internal pointer to the prototype objec

Javascript basics and javascript beginners are recommended in javascript beginners. Some time ago, when I read the javascript advanced tutorial, I found many basic javascript concepts that I don't understand. I searched the internet and saw that 《Basic

First, why use Require.js. At the earliest, all of the JavaScript code was written in a file, and it was enough to load the file. Later, more and more code, a file is not enough, must be divided into multiple files, sequentially loaded. The following page code, I believe many people have seen. This code loads multiple JS files sequentially. There are a lot of drawbacks to this way of writing. First of all, when loading, the browser will stop the page

}) (Window, documen T, JQuery); Even the front-end modular loading solution, such as Requirejs, Seajs, Ozjs,Are all in a similar form: Copy code code as follows://Requirejsdefine ([' jquery '], function ($) {//main business code});//Seajsdefine (' m?? Odule ', [' dep ', ' underscore '], function ($, _) {//main business code}); If you say that many of the code for the node. JS Open source project is not handled this way, you are wrong. node. js, before

, such as getage (), the function's this points to the global object, which is window Use Apply to repair Getage () Call function Getage () { var y = new Date (). getFullYear (); return y-this.birth; } var xiaoming = { name: ' Xiaoming ', birth:1990, age:getage }; Xiaoming.age (); getage.apply (Xiaoming, []);//, this points to xiaoming, the argument is null apply () A similar method is call (), the only difference is: Apply () to package the parameters into an array and th

"); }. Bind (this), opts. freq | 100 );} // Assume that we have inherited the event sender (EventEmitter );) When it cannot be run, functions equivalent to. bind are provided in most modern JavaScript libraries. The Code is as follows: // 6. B .2 // Example: lodash/underscore, _. bind ()Function Device (opts ){ This. value = null; Stream. read (opts. path, _. bind (function (data ){ This. value = data; }

arrayElements = []. slice. call (elements); // now the Array has been converted to var arrayElements = Array. from (elements); // another method for converting NodeList into an array 12) shuffling array elements To shuffles data elements like the external library Lodash, you only need to use this technique: var list = [1, 2, 3]; console.log(list.sort(function() { return Math.random() - 0.5 })); // [2,1,3] Conclusion Now you have learned some useful JS skills, which are mainly used to reduc

This article mainly introduces how to implement the inheritance of javascript and how to learn javascript object-oriented. If you are interested, refer to the examples in this article to introduce 6 methods for implementing the inheritance of javascript, the content is as follows: 1. [prototype chain inheritance]The essence of implementation is to override the p

Document directory Event example: Events are behaviors that can be detected by JavaScript.Event Javascript enables us to create dynamic pages. Events are behaviors that can be detected by JavaScript. Each element in the web page can generate events that can trigger JavaScript Functions. For example, when a user clicks a button, an onclick event is generated

Javascript is a sequence of statements executed by the browser. Javascript statements The javascript statement is a command sent to the browser. These commands are used to tell the browser what to do. This JavaScript statement tells the browser to output "Hello World" to the webpage ": Document. Write ("Hello W

as RequireJS, SeaJS, and OzJS all adopt similar forms: // RequireJSdefine (['jquery '], function ($) {// main business code}); // SeaJSdefine ('module', ['dep ', 'underscore '], function ($, _) {// main business code }); If you say that the Code of many Node. js open-source projects is not handled in this way, you will be wrong. Before running the code, Node. js packs each. js file into the following format: (Function (exports, require, module, _ dir

that cannot be displayed starting with a backslash. It is usually called a control character.　3. VariablesVariables are mainly used to access data and provide containers for storing information. For a variable, you must specify the name, type, declaration, and scope of the variable.Variable nameThe naming of variables in Javascript is very similar to that in computer languages. Note the following:A. It must be a valid variable, that is, the variable

JS framework Learning 1. Underscore http://documentcloud.github.com/underscore/========================================================== ======================================Underscore is a utility-belt library for JavaScript that provides a lot ofFunctional programming support that you wowould have CT in prototype.

Comparison of the Javascript efficiency of various Javascript browsers it is reported from an article on "translated words" that the comparison of Javascript in various browsers. As a Javascript developer, I personally pay more attention to this matter. I still trust SunSpider in the test area, as the original article

Javascript is a scripting language designed for interaction with Web pages. It is constructed by the following three departments l ECMAScript, defined by a ECMA-262, defining the rules and conventions of the javascript language, it is like the rules, specifications, and conventions specified for starting a game. L DOM: provides methods and interfaces for accessing and operating webpage content L BOM, which

Javascript: Javascript special effect: convert HTML into Javascript code automatically. Sometimes you need to use Javascript to enter common characters, such as a footer for every page. Here is a conversion script: SCRIPT function Preview (obj) {var TestWin = open (''); TestWin.doc ument. write (obj. value);} function

The 2.1.2 Delay script refers to the defer property and only applies to external scripts, that is, scripts that have defer properties.Delaying scripts at the bottom of the page is still the best choice due to the lack of uniform support for deferred scripting by various delay browsers and the fact that the defer attribute is no longer supported after HTML5.2.1.3 Asynchronous Script The second script may be executed before the first script, so it is important to ensure that two scripts are not d

, you may get an error message such as "Identifier expected" (which should have identifiers, expected identifiers). Note: If you use a reserved word as a variable or function name, you may not receive any error messages unless the future browser implements the reserved word. When the browser implements it, the word is treated as a keyword, so a keyword error occurs. Here's a description of the JavaScript language identifier Identifiers are names th

can be any length. When you create a variable name, you need to follow these command rules:{1}, the first character must be a letter or an underscore (_), cannot be text, the number cannot be used as the first character and cannot use punctuation, operation symbols.{2}, variable names are strictly case-sensitive. For example, the variable name mycounter is different from the variable name mycounter.{3}, variable names cannot be