es6 for beginners

ES6 (ECMAScript 6) is the upcoming new version of the JavaScript language standard, code-named Harmony (meaning of harmony, obviously did not keep pace with our country, we have entered the Chinese Dream version). The last standard was enacted in 2009 ES5. The ES6 is currently in the process of standardization and is expected to release the officially finalized version in December 14. But most of the standa

it down.) This is the most obvious difference.Sea.js sea.use() to load the module.Seajs.use (ID, callback?)ES6ES6 module features, recommended see Nanyi Teacher's: ECMAScript 6 Getting Started-module syntaxSpeaking of ES6 module characteristics, then first talk about the difference between the ES6 module and the CommonJS module. The ES6 module outputs a

Brief introductionWelcome to the Deep Exploration es6! In this new week series, we will explore ECMAScript 6. This is a new version of the JavaScript language that is coming soon. ES6 contains a lot of new language features, and these language features make JS more powerful and expressive. In the next few weeks, we'll get to know these new features one by one. But before we get into the details, it's worth

Block-level scopes ES5 does not have block-level scope, only global scope and function scope, because of this, the scope of the variable is very wide, so a entry function is to create it immediately. This creates the so-called variable ascension. ES5 's "variable Elevation" feature is often inadvertently caused by a mistake: 1. Inner variables cover outer variables var tmp = new Date (); function f () { console.log (TMP); if (false) {//execute undefined var tmp = "Hello World"; } }

Can a function be declared in a block-scoped scope? This is a rather confusing question.ES5 states that functions can only be declared in the top-level scope and function scope, not at the block-level scope.1 //situation one2 if(true) {3 functionf () {}4 }5 6 //Scenario Two7 Try {8 functionf () {}9}Catch(e) {Ten // ... One}The above two function declarations, according to the provisions of ES5 are illegal.However, the browser does not adhere to this rule, in order to be compatible with the

advance.B.foo ()}});CMD is another JS modular scheme, and it is similar to AMD, the difference is that AMD respected the reliance on pre-and early-execution, CMD respected near-dependency, deferred execution. This specification is actually produced in the process of sea.js promotion./ AMD notation /Define (["A", "B", "C", "D", "E", "F"], function (A, B, C, D, E, f) {is equal to the first declaration and initialization of all modules to be usedA.dosomething ();if (false) {Even though it didn't w

1. Overview Historically, JavaScript has never had a module system to split a large program into interdependent small files, and then assemble them in simple ways. Other languages have this feature, such as Ruby require, Python import, and even CSS have @import, but JavaScript does not support any of this, which is a huge obstacle to developing large, complex projects. Before the ES6, the community developed a number of module loading programs, the m

http://es6.ruanyifeng.com/#READMEHttps://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference(1) Arrow operatorIf you have C # or Java, you must know the lambda expression, the new arrow operator in ES6. It simplifies the writing of functions. The left side of the operator is the input parameter, and the right side is the action to be taken and the value returned inputs=>outputs.We know that the callba

, Elem = C The for-of loop of the ES6 supports ES6 iterations (through Iterables and iterators) and deconstruction. If you use the new method of the array enteries () to combine the deconstruction, you can achieve the same effect as the above ForEach: Const arr = ["A", "B", "C"]; for (const [index, elem] of arr. Entries()) { console. Log('index = ${index}, ele

React native is the direct use of ES6 to write code, many new syntax can improve our productivityDeconstruction Assignmentvar { StyleSheet, Text, View} = React;This code is the new deconstruction (destructuring) assignment statement in ES6. Allows you to get multiple properties of an object and assign them to multiple variables using a single statement.The above code is equivalent to:var StyleSheet = Rea

Why do ES6 have compatibility issues? Because the majority of users use the browser version at the time of release may be earlier than the ES6 and release, and today, if we use the new features of ES6 in programming, if the browser does not have a newer version, or the new version of the ES6 features are not compatible

Module referenceIn ES5, if the CommonJS standard is used, The React package is introduced through require. The code is similar to this:// ES5Var React = require ("react-native ");Var {Image,Text,View,} = React; // reference different React Native componentsIn ES6, the import statement is more standard.// ES6Import React ,{Image,Text,View,} From 'react-native ';Note that only versions later than React Native 0.12 support the import sy

1, the tag is opened defer or the async property , the script will be loaded asynchronously. When the rendering engine encounters this line of command, it begins to download the external script, but does not wait for it to be downloaded and executed, but executes the following command directly.deferasyncthe difference is that the former will not be executed until the entire page is rendered normally, and once downloaded, the rendering engine interrupts rendering, executes the script, and then

In view of the recent development of projects with the VUEJS framework, many of them involve the ES6 grammar which is not well understood in order to read the book carefully.Address: http://es6.ruanyifeng.com/#README　　Chapter One: Let, const commands, and block-level scopesES6 adds a declarative keyword for both the Let and the const variables, which greatly reinforces the JS variable's reasonableness and f

Turn:Using Webpack for ES6 developmentSome digressionThe original intention of using Webpack is actually to use React.When learning React, there is always a problem: Since the component is modular, such as a jsx file corresponding to a component, this file contains the HTML and JS of this component, but where should his style be written? The online tutorials are written in the Jsx file, defined by variables, or written directly into the global style.