es6 book

1.array.from ()(1) converting to an arrayThe ①array.from () method canclass Array Object (The so-called array-like object, the intrinsic feature is only one point, that is, the length property must be. Therefore, any object with the Length property can be converted to an array by means of the Array.from method , at which point the extension operator cannot be converted. )and Ergodic (iterable) objects into real arrays. Includes ES6 new data structure

1. Let commandTips: Block-level scope (valid only in the current block) No variable promotion (must first be declared in use) Let the variable monopolize the block, no longer subject to external influence Duplicate declarations are not allowed In short: Let's more like the variable declaration directives of the static language we know wellES6 has a new let command to declare variables. The usage is similar to Var, but the declared variable is valid only within the code

ES6 today officially released (Roadside News), anyway, it will be released this month, before a lot of ES6 features have been fired very hot, but the total feeling and we have little relationship, because either some have not supported, or practicality is not very large, But today is a method that you must be familiar with or have used or heard.Believe that engaged in the front-end must have used angular ba

A simple example of using babel to convert es6 syntax to es5, babeles6 syntax es5 Preface Babel is a widely used Transcoder that can convert ES6 code into ES5 code for execution in an existing environment. This means that you can write programs in ES6 now without worrying about the support of the existing environment. This article describes how to pre-insta

ES6 provides MAP, it is a set of k-v pair. Key can be number, string, object, function and even undefined.var New Map ();Methods: 1. Set (K,V)M.set ("edition", 6) // key is the string m.set (262, "standard") // key is numeric M.set ( Undefined, "nah") // key is undefinedvarfunction() {console.log ("Hello" // key is a function2. Get (k)M.get (Hello) // Hello es6! M.get ("edition")

Preface: After so long, small rookie finally began to formally apply react, and ES6 to develop the project. Before like a classmate of a blog style, here to paste the address: Https://iwenku.net/,PC End is what he did long ago, he recently re-made a move. After reading, I also sketched out a blog, so I began to formally build their own blog as a project practiced hand bar. First, build the environment1, install nodeThe first step is to make sure

Array.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).1Let Arraylike = {2' 0 ': ' A ',3' 1 ': ' B ',4' 2 ': ' C ',5Length:36 };7 8 //the writing of ES59 varARR1 = [].slice.call (arraylike);//[' A ', ' B ', ' C ']Ten One //the writing of ES6 AL

Today Vue Project NPM Run build after Webpack, error UGLIFYJS, their own research, translated, meaning is not recognized in the project to write advanced grammar, here to the project ES6 syntax es5 let the browser recognize,That is Webpack's Babel need to be configured underBabel is actually a platform for compiling JavaScript, and its strength is that it can be compiled to help you achieve the following: Use the next generation of JavaScript co

Commonjs and AMD essentially define a namespace with a global variableTake Sea.js as an example, each module outputs an object, and the object is mounted under the Seajs.cache property, and each module exists as an object.While the ES6 module is not, the module object does not exist when the module is not referenced.Commonjs and AMD are run-time loaded, ES6 modules are loaded at compile timeThis distinction

The first thing to say is the array: the array is classified as object, which is a special object, and the index value of the array is similar to the object's key value.Several points of note for arrays :1. The length of the array is a readable property and cannot be changed, and the length of the array is based on the index maximum value.2. The index value of an array can be a string, etc., but this does not affect the length of the array.3. The array is automatically filled with the correspond

A few new ways to ES6 arrays:1. ForEach ()// ForEach () iterates through an array with no return value and does not change the original array var arr=[1,2,3,4]arr.foreach ((item,index,arr)={ console.log (item); // 1,2,3,4})2. Map ()// map () iterates through an array, returns a new array, and does not change the value of the original array var arr=[1,2,3,4]arr.map ((item,index,arr)={ return item*10; // returns the new array 10,20,30,40})3

, Date.now3.Object method Object.getprototypeofObject.createObject.getownpropertynamesObject.definepropertyObject.getownpropertydescriptorObject.definepropertiesObject.keysObject.preventextensions/object.isextensibleObject.seal/object.issealedObject.freeze/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:Th

ES6 provides us with two data structures set and map, which are sometimes convenient for us to process our data. The two methods are analyzed directly. One, set data structure Set itself is a constructor that is used to generate set data structures, similar to arrays, but whose values are unique.The set internally determines whether two values are different, similar to the exact equality operator (= = =), the main difference being that nan equals itse

; Son.prototype.getAge=function() {Console.log ( This. age);}//Create an instancevarStudent1 =NewSon (' ASD ', ' 11 '); Student1.getname ();//ASD, a method inherited from a parent classStudent1.getage ();//11, subclasses of their own methodsInheritance of classes in ES6//class and inheritance in Es6//creating a parent classclass parent{Constructor (name) { This. Name =name; }//!! Note that there are no comm

operation are the sum of the information that "every moment" can get. Ordinary people are relatively "comfortable", if the human and the environment are "God" written procedures, then this "God" is not so "comfortable". Because, "he" needs to be pre-considered in each scenario, each of the various possible evolution. As a programmer, for the written program, to some extent, the role of "God". (see here, is not a bit of a feeling of being smug) But we do not have the ability, our thinking is sti

ES6 const usage, es6const usage 1,ConstDeclare a read-only constant. Once declared, the constant value cannot be changed. 2,ConstScope andLetThe command is the same: onlyBlock-level scope. 3,ConstThe constants declared by the command are not upgraded.And can only be used after the declared position. 4. ES6:VarCommands andFunctionThe global variable declared by the command is still the attribute of the t

Since the beginning and end of the separation, the front-end project engineering has become more and more important, before writing a building based on Angular+Requirejs+Grunt the front-end project tutorial, interested can point here to seeBut some projects can be used this way, but some are not, or we just want to try a new framework. For example, I recently tried to use webpack+react+es6 the way to develop projects, feeling very good, and then many

Class Es5 generates instance objects through Constructors function User(name, pass) { this.name = name this.pass = pass}User.prototype.log = function () { console.log(‘name = ‘ + this.name + ‘, pass = ‘ + this.pass)}var user1 = new User(‘xiaoming‘, ‘12356‘)user1.log()//name = xiaoming, pass = 12356 Es6 introduces the concept of class and constructor. When defining a "class" method, you do not need to add the function keyword before. Methods d

The ES6 copy Array object has the following methods:method One: object.assign () // object Shallow Copy, obj1 Copy to Obj2, this method to set Obj2 {}, not const OBJ2 = ""; Const OBJ1 = {a:1= {};object.assign (Obj2, Obj1) method two: ES6 extension operator (...) // object Shallow Copy, obj1 copy to obj2const OBJ1 = {a:1= {... obj1}; method Three: Deep copy // object deep Copy, obj1 copy to obj2= Json.parse

1. The difference between let and const:1) Let can be modified, const is a constant cannot be modified;2. The difference between Let,const and Var:1) Let,const There is no variable promotion; So don't worry about pre-interpretation and scope issues;2) repeated declaration of the same variable is not allowed under the same block-level scope;3) ES6 allows declaring functions within a block-level scope,A function declaration is similar to, that is, var p