es6 for beginners

consideration, we also need to use logic like this in each of the callback layers try...catch . This is the source of all evils and the point at which node is beginning to be widely criticized. Another disadvantage is that, assuming there is no dependency between our three saves, we still need to wait for the previous function to finish before we can perform the next step, instead of three to save the parallel, and then return a three saved result after the save. (or to implement it requires s

Modules is one of the most important features introduced by ES6.So later write the module, directly according to ES6 modules syntax to write, and then use Babel + Browserify to package on the line. The modules specification is divided into two parts, part of how it is exported, and part of how it is imported. Basic Usage named export (named exports) You can export it directly by adding an export keyword to

( This. name);}functionSubtype (name,age) {//Inheritance PropertiesSupertype.call ( This, name);//Call Supertype The second time you create an instance This. Age =Age ;} Inherit (subtype,supertype);//implementing parasitic combined inheritance Let's take a look at the core function that implements parasitic combined inheritance. The F function is actually generic, and we don't need to declare it every time we enter the inherit function. So we can write in the form of closures: varInherit =

Please specify the Source: Grape City website, Grape City for developers to provide professional development tools, solutions and services, empowering developers. Original source: wanago.io/2018/07/16/webpack-4-course-part-one-entry-output-and-es6-modules/ How are you doing! Today we will start a Webpack 4 introductory tutorial. We will start with the basic concept of webpack, as the tutorial progresses. This time, we will learn the basics of modu

Copyright belongs to the author.Commercial reprint please contact the author for authorization, non-commercial reprint please specify the source.Zhang XuanLinks: http://zhuanlan.zhihu.com/p/20367175Source: KnowIf you do not have the ES6 grammar support now, it is a little bit of force, in fact, we all know this is also very simple, because we have a great BabelStart with a variety of loadernpm install babel-loader babel-preset-es2015 --save-devConfigu

Metaprogramming refers to the "programming the language itself" by developers ". Generally, the programming language exposes some APIs for developers to operate on certain features of the language. Starting from ES6, the Proxy and Reflect features have been added, and meta programming has been extended (MetaPro... meta programming refers to developers programming the language itself ". Generally, the programming language exposes some APIs for develope

definition implements a module is divided into Module reference module to define module identification (require () the identity used at the time) This is a simple example of the official website This is an exampleJS Modularity in the browser this way is absolutely no problem in node, but the first problem in the browser is require module.exports These keywords are not supported in the browser That is, we need the module loader to help us implement the require to load the Commonjs module. Anothe

1.let and Const commands1.ES6 new Let and const commands, similar to Var usages, but the variables it declares are valid only within the code block where let is located (block-level scope, ES5 only global and function scopes){let a = 1; var b = 2; } //A is not a variable declared by defined let only within its own block valid //2 varA = []; for(AVR i = 0; i ){A[i] =function() { Console.log (i) }; } A[3] ();//Ten //A[3]) () print out

(x);}//Output://Hello// WorldAt line A, the symbol object is used as a key, and the key value is a method. This unique key allows the object to iterate and can be used for for-of looping.Purpose 2: Use constants to represent special meaningsIn ECMAScript 5, you might use strings to represent special meanings, such as colors. In ES6, you can use symbol because symbol is always unique:Constcolor_red = Symbol ('Red');ConstColor_orange = Symbol ('Orange'

Deconstruct and assignment of ES6 learning variables Deconstruct and assignment of Variables In ES6, variables can be extracted from arrays and objects in certain modes and assigned values. Deconstruct and assignment of Arrays var [a,b,c] = [1,2,3];a // 1;b // 2;c // 3; The code above indicates that values can be extracted from the array and assigned values based on the corresponding positions. Essentially,

ES6 modular import and export usage method summary, es6export Before ES6, The js module loading scheme has emerged. The most important is the CommonJS and AMD specifications. Commonjs is mainly used on servers for Synchronous loading, such as nodejs. AMD specifications are used in browsers, such as requirejs, for asynchronous loading. There are also CMD specifications for Synchronous loading solutions such

);*/ theConsole.log ("This dog is eating" +Food ); - }; - - functionCat () {} + varCATP =extend (cat,animal); -Catp.eat =function(food) { +Console.log ("This cat is eating" +Food ); A }; at varSnake =NewSnake (); -Snake.eat (' mouse ');//log: The animal is eating mice - varDog =NewDog (); -Dog.eat (' Bones ');//log: This dog is eating bones . - varCat =NewCat (); -Cat.eat (' fish ');//log: The cat is eating fishAbstract class:In the above code, the snake class does n

In this article I will take my understanding of the new feature class of JavaScript es6. In the spirit of sharing the Internet, I will share my own understanding to everyone.Write a class (constructor) using ESIn ES5, it's common for everyone to write a class (constructor)It is also important to note that class classes are not promoted.//Create a user constructorfunctionUser (name, age) { This. Name =name; This. Age =Age ;}//the static method of the

some elements, could it? Yes, the Fill () function provides parameters that specify the starting and ending positions of the fill.Or the above case, let's make a slight adjustment and then demonstrate:1 Let arr = [n/a]; 2 Arr.fill (4,1,3); 3 Results: [1,4,4]The 2nd and 3rd parameters in the above code mean that the element starting at position 1 is filled with the number 4, until position 3, so that the element of position 1 and position 2 is filled with the number 4, resulting in th

Previous wordsThe training array is a dedicated array for processing numeric types (as its name, not all types) of data, originally used in WebGL, a ported version of OpenGL ES 2.0, which is presented in a Web page through the OverviewIn JS, numbers are stored in 64-bit floating-point format and converted to 32-bit integers on demand, so arithmetic operations are slow enough to meet the needs of WEBGL. Therefore, the training arrays are introduced in ES6