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
ES6 Essay--Extension of each data type (4)--extended extension operator for arrays and arrays of objectsThe form is three points, which is used to convert the ...数组 array to a comma-separated parameter sequence; equivalent to rest the inverse of a parameter;An extension operator can be followed by an expression, or an empty array without any effect;An extension operator can expand an array, instead of apply passing a parameter array to a function;// 扩
Expansion of arrays
1.1 extension Operators 1.1.1: ...The extension operator (spread) is a three-point ( ... ). It is like the inverse of the rest parameter, converting an array to a comma-delimited sequence of arguments. This operator is primarily used for function calls. function Add (x, y) { return x + y; } var numbers = [4,]; // theIn the above code, the add(...numbers) function is called, and it uses the extension operator. The
One, the copy of the arrayalert ([1,2,3]==[1,2,3]);Let CC = [0,1,2];let DD = CC;alert (DD==CC);//changing DD at this time will affect CCES5 can only use workarounds to copy arrays.= [1, 2];const a2 = a1.concat();a2[0] = 2;a1 // [1, 2]Using ES6 syntax prevents this behavior from appearingconst A1 = [12 ]; notation a const A2 = [..a1];//notation two const [.. .a2] = A1 alert ([' C ']==[' C ']);//falsealert ([' C ']===[' C ']);//falseExpansi
We used to define variables using Var, and ES6 gives us two ways to let and const (const is defined as constants). Today I will summarize let and Const. Simple, big god bird me. One, let define variable.
We use a let-defined variable and a variable defined by VAR in es5 to differentiate.
1. Let-defined variable with block-level scopeWhat is a block-level scope, like {} curly braces, is a block-level scope. So let is declared within the block-level sco
IntroductionThe current react front-end frame is the hottest this year. React native, based on react, also developed rapidly. React has its unique component function and jsx new syntax to help the front-end design with better design and convenience, and react native is to expand the front-end boundaries.Speaking of react, you have to say that Webpack, with its excellent features such as asynchronous loading and detachable packaging, is on the way to replace grunt and gulp. And the future-oriente
This article describes how to parse the deconstruct assignment in the JavaScript ES6 version. The ES6 version has brought many simplified improvements to JS. If you need it, What Is deconstruct assignment?
Deconstruct value assignment allows you to assign values of arrays and objects to a series of variables using syntax similar to arrays or object literal values. This syntax is concise and clearer than tr
ES5 's top-level object itself is also a problem, because it is not unified in various implementations.
Inside the browser, the top-level object is window , but Node and Web Worker do not window .
Inside the browser and Web Worker, self It also points to the top-level object, but Node does not self .
Node, the top-level object is global , but no other environment is supported.
The same piece of code in order to be able to take the top-level objects in various environments,
1. ES6 string Changes(1) The includes () method returns False if the specified text in the string is detected to return true(2) The StartsWith () method returns True if the text is detected at the beginning of the string, otherwise false(3) The EndsWith () method returns True if text is detected at the end of the string, otherwise falseAll of the above methods receive two parameters, one is the text to be detected, the second parameter is optional, th
ES6 (ECMAScript 2015) coding specifications and detailed attention points, combined with a large number of GF securities ES6 practice projects organized,Already open from GitHub, continuous update, welcome PR and issue.GitHub Address: https://github.com/gf-web/es6-coding-style/This specification is based on the JavaScript specification and is only intended for
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