es6 course

Then the above [JS Master Road] ES6 series tutorial-iterator and builder details continue.A new loop structure was introduced in ES6 for ... of, mainly used to iterate over an iterative object, so what is an iterative object?An iterative object typically has a Symbol.iterator property, and you can print an array with Console.dir in the console, Map,set, which can be found on their prototype object (prototyp

JavaScript,JavaScript is a scripting language with its own syntax and semantics, without JavaScript, and no other concepts.About ES6, which can be directly understood as the enhanced version of JavaScript (adding new specifications, features and functionality) or the latest version, although slightly different, but also can be ignored (do not care about these details, hehe), a bit similar to the JAVA8 and Java language relationship, Also since there a

Deconstruction Assignment of arraysES6 allows you to extract values from arrays and objects in a certain pattern, assigning values to variables, which is called deconstruction (destructuring).Previously, assigning a value to a variable could only be specified directly.let a = 1;let b = 2;let c = 3;ES6 allowed to be written as follows.let [a,b,c] = [1,2,3];console.log(a); // 1console.log(b); // 2console.log(c); // 3The following will also be parsedlet

CP from:https://www.cnblogs.com/ricoliu/p/5996149.htmlMet with a puzzle that was originally called ES6, and now suddenly becomes es2015.The reason for this is the sixth change in ecma-262, all formerly known as ES6.But in order to be released frequently for smaller versions, it is now the standard term: Esmascrip 2015Baidu Information:As of the release date, the official name of JavaScript is ECMAScript 201

Installing BabelThe official documentation suggests that we install locally based on a single project because different projects can rely on different versions of Babel to make your project more portable and easier to install.Use the command line tool (CMD, etc.) in the root directory of the project to execute the following codenpm install --save-dev babel-cliInstall compilation rulesThe official set of preset sets of rules are available for some of the experimental features of ES2015, React, an

Objective For JavaScript, classes are optional (not necessarily) design patterns, and implementing classes in [[Prototype]] languages like JavaScript is lame. This kind of lame feeling is not just from grammar, although grammar is a very important reason. JS has a lot of grammatical shortcomings: cumbersome and messy. Prototype refers to explicit pseudo polymorphism when attempting to invoke a function of the same name on the upper layer of the prototype chain and is unreliable, unattractive,

Variables declared by let and Const are valid only within the code block {Let a = ten; var b = 1; } A//REFERENCEERROR:A is not defined. b//1 There is no variable elevation Variables must be used after declaration, otherwise the error var tmp = 123; if (true) { TMP = ' abc ';//Referenceerror let tmp; } Do not allow duplicate declarations Error function () {Let a = ten; var a = 1; } Block-level scopes function f () {Console.log (' I am outside! ');}

Objective A few years ago, when SpiderMonkey implemented a rigorous model. I learned that strict mode disables the octal integer literal. Because there is evidence that some beginners will use the leading 0来 to align numbers in multiple lines, leading to unexpected results: var sum = 015 +//equivalent to decimal 13, rather than 197 + 001; Anyway it's 1 console.log (SUM)//Added and is 211, not the novice thinks 213 But there are still a number of developers who need to oc

Let is the new copy command inside the ES6, let assignment commands can only be invoked in the {} code block. Here is an example to explain the Let command in Es6, the details are as follows: The use of the 1.let command is similar to the Var command, but the variable declared by the Let command is valid only within the code block of Let {Let a=10; var b=1; } Console.log (a);//uncaught referenceerror:

Preface: because mixin is contrary to JavaScript semantics, React ES6 uses higher-order components instead of mixins. In This section, we will focus on how to replace the traditional React mixins with higher-order components. How do we use ES6 to handle mixin? What is a high-order component? Adding logic to an existing component class through a function is a higher-order component.A higher-order component

Webpack Reference Document: https://www.valentinog.com/blog/webpack-4-tutorial/ React: Reference Document: Https://reactjs.org/docs/add-react-to-a-new-app.html ES6 Reference Document: http://www.ruanyifeng.com/blog/2017/09/es6_primer_3rd_edition.html Let ' s start First, install the operating environment: node. js 1. Application Download Address: https://nodejs.org/en/ NODE-V View node version (my v9.9.0v); npm-v my version (v5.7.1) 2. Install yarn-de

Three, ArrayThe array object adds some new static methods, and some new methods are added to the array prototype.1.array.from to create an instance of an array from an array of classes and traversed objects　　Class array objects include: arguments in Functions, NodeList objects returned by document.getElementsByTagName (), newly added map and set data structures.In ES6 class array conversion method let Itemelements=document.queryselectorall ('. Item ')

This is a creation in Article, where the information may have evolved or changed. ES6 allows values to be extracted from arrays and objects (as well as strings, values, Booleans, function parameters, and so on) in a certain pattern, which is called a deconstructed assignment, by assigning a value to the variable in the corresponding position. First, assuming that you already know what a deconstruction assignment is, let's take a quick look at its comm

1. codePointAt method is the simplest way to test whether a character consists of two bytes or four bytes.1 function Is32bit (c) {2 return c.codepointat (0) > 0xFFFF; 3 }45// true6// false2.ES6 provides methods for string instances to normalize() unify different representations of characters into the same form, which is called Unicode normalization.normalizeMethod can accept four parameters. NFC , the default parameter, means "standard

This article describes in detail how to use Set and WeakSet in ES6. If you are interested, refer to the two new data structures-Set and WeakSet in ES6. Set is similar to an array, but the values of member variables are unique and there are no repeated values. WeakSet is also a set of non-repeated values, but can only be used to store objects. 1. Set usage (1) Set itself provides a constructor to generate a

ES6 and canvas implement the following effect on the mouse ball and es6canvas ball Recently, I was bored. I read ES6 syntax and used canvas to implement animation effects. As the mouse moves, there will be an animation where the ball follows and disappears automatically. First, the html part is currently a canvas tag. 1 Secondly, the css section does not consider appearance. If you like it, you can add you

: [ /// New Webpack.optimize.UglifyJsPlugin ({ // compress: { // warnings:false // } // }) // ]};　　Module features include jsx to Js,es6 es5,scss to CSS,Here I use a built-in plugin for Webpack, which UglifyJsPlugin allows you to compress the generated files, which I commented out.1.3 On the CodeThen we'll give you the important code.Index.htmlDOCTYPE HTML>HTMLLang= "en">Head> MetaCharSet= "UTF-

There are two new commands in ES6: Let and Const.Let command: let is used to declare a variable, similar to Var, but the declared variable is valid only in the code block, there is no promotion of the variable, there is a temporary dead zone.1. Valid only in code blocksUnlike the Var command, a let declared variable is only valid in a block of code, such as{ = 1; var b = 2;}Console.log (b); Print 2;console.log (a); This would cause error.2. There is

I believe many people have used export, export default, import, but what is the difference between them?In JavaScript ES6, export and export default can be used for exporting constants, functions, files, modules, etc., which you can import in other files or modules in such a way that they can be import+(常量 | 函数 | 文件 | 模块)名 used, but in a file or module, Export, import can have multiple, export default only one.Specific use:1.//demo1.jsexport const str

Today began the study of ES5 and ES6.1. What is ES5 and ES6?is the fifth and sixth version of ECMAScript, so the question is, what is ECMAScript? First it is a scripting language, called JavaScript, that is standardized by the ECMA international through ECMA-262, but in fact JavaScript is the implementation and extension of the ECMA-262 standard ( Said so much in fact it is a set of JavaScript standards, the specific name of the origin and history can