es6 book

In ES6, the variable deconstruction is this:Const A = {b:1}const {b} = aWe can use the destructor assignment directly to get the property of the object with the same name, which is equivalent to:Const B = a.bIn addition to the destructor assignment of variables, ES6 's module import also provides similar syntax:Import {Resolve} from ' path 'If you use Webpack to build a project, be aware that the deconstruc

Meaning of the 1.Promise:Promise is a solution for asynchronous programming that is more logical and powerful than traditional solutions-callback functions and events. It was first proposed and implemented by the community, ES6 wrote it into the language standard, unified the usage, the native provided the Promise object.The so-called Promise simple is a container that holds the result of an event (usually an asynchronous operation) that will end in a

In the ES6 new fast-scope concept (C language, as C-language JS, of course, should be added), is very good understanding.{let i;} Console.log (i); // i am not definedUse the new scope in the code block.The problem is that the FOR statementLet arr=[]; for (Let i=0;i) { arr[i]=function() { console.log (i); };}Many of the explanations do not specifically describe how the scope of the work is seen, and it seems to be a natural thing.Howev

Many languages have block-level scopes, but JS does not, it uses VAR to declare variables, the function to divide the scope, curly braces "{}" does not limit the scope of var. Variables declared with VAR have the effect of variable promotion (declaration hoisting).A let is added to the ES6, which can be declared in {}, if, for. The usage is the same as Var, but scoped at the block level, the let declared variable does not have a variable promotion.Exa

ES5 constructor: function F (name) { this . Name = name; // private property } f.prototype.writecss = function () {Console.log ( ' writecss '); // The method on the prototype "F.writejs = function () {// console.log (' js ' Class of ES6: class f{ Constructor (name) {/// put private property, which is equivalent to the contents of the constructor in Es5 . Name = name; }; Writecss () {// method Console.log

Many languages have block-level scopes, but JS does not, it uses VAR to declare variables, the function to divide the scope, curly braces "{}" does not limit the scope of var. Variables declared with VAR have the effect of variable promotion (declaration hoisting).A let is added to the ES6, which can be declared in {}, if, for. The usage is the same as Var, but scoped at the block level, the let declared variable does not have a variable promotion.Exa

ES6 can use the arrow to define a function, note that it is a function, and do not define the class (constructor) in this way.First, the grammar1. Simple function with one parametervar single = a + asingle (' Hello, World ')//' Hello, World '　　2. Need to use the parentheses before the arrows for no parametersvar log = () = { alert (' No Param ')}　　3. Multiple parameters need parentheses, comma interval between parameters, e.g. two numbers addedvar

ES6 has added many support for internationalization, such as time format, currency format, and digital format. Internationalization amp; Localization (Internationalization and Localization) refers to the language for modifying software to adapt to the target market... ES6 has added many support for internationalization, such as time format, currency format, and digital format. Internationalization Loca

, String.prototype.trim, Date.now3. The Object method///Object.isfrozenPS: There is nothing to say but what to say.What is ES6ECMASCRIPT6 provides a number of new features in the context of guaranteed backwards compatibility, and is currently compatible with the following browsers:The ES6 features are as follows:1. Block-level scope keyword let, constant const2. Attribute assignment shorthand for object literals (property value shorthand)var obj = {

Reactjs Learning One (environment collocation react+es6+webpack Heat Deployment)Reactjs this year in the front end of the ring is very fire, with three or four months, it is really suitable for front-end developers to use, it is worth digging, so here is a record of my simple learning process, the first is the react environment, because now react new version is very stable, so the recommended use es6+ Webpa

To use Babel, we need NODEJS environment and NPM, the main installation of Nodejs, NPM installed by default, now installed Nodejs is very simple, directly download the installation is good;Installing Es-checkerBefore using Babel, we need to check the current node support for ES6, we use the first Es-checker, the command line execution:Npm-g Install Es-checkerEs-checker after installation, command line execution:es-checker , for example, my node enviro

Expansion of arraysArray.from ()Array.fromThe Array-like method is used to convert two types of objects to a true array: An array-like object (A. iterable) and an object that can be traversed (including ES6 new data structure set and map). let arraylike = ' 0 ': ' A ' , ' 2 ': ' C ' 3}; // ES5 the notation var arr1 = [].slice.call (arraylike); // [' A ', ' B ', ' C '] // ES6 's notation let arr2 =

VUE-es6, Es6: Es: EMCAScript 6 (es2015) Emca: International Standards Organization I. constants and variables Const a = 'hello' constant const can be defined only once and cannot be repeated The value of the variable declared by const cannot be changed, which means that once the variable is declared by const, it must be initialized immediately and cannot be left for future value assignment. The let Command

contained in this example is Package.json, which is the least installation of WEBPACK+REACT+ES6 development. This example hot load, modify any one src/js under the JS file, save, the browser automatically updated.2) This example does not install React-hot-loader, because it is installed directly, the current version of one to 3.0 or more, and does not support the writing in Webpack.config.js:{test:/\.js?$/, exclude:/node_modules/, loaders: [' react-h

, String.prototype.trim, Date.now3. The Object methodObject.getPrototypeOfObject.createObject.getOwnPropertyNamesObject.definePropertyObject.getOwnPropertyDescriptorObject.de Finepropertiesobject.keysobject.preventextensions/object.isextensibleobject.seal/object.issealedobject.freeze/ Object.isfrozenps: There is nothing to say but what to tell.What is ES6ECMASCRIPT6 provides a number of new features in the context of guaranteed backwards compatibility, and is currently compatible with the follow

ES6 New Data Structure Map function and usage example, es6map This example describes the functions and usage of ES6's new data structure Map. We will share this with you for your reference. The details are as follows: New data structure Map In Javascript, objects are essentially a set of key-value pairs, but keys can only be strings. To make up for this defect, ES6