es6 course

What is the deconstruction assignment. The deconstruction assignment allows you to assign the properties of arrays and objects to various variables using syntax such as array or object literals. This assignment syntax is extremely concise and is much clearer than the traditional method of accessing property. In general, you are likely to access the first three elements of the array in this way: var-i = somearray[0]; var second = somearray[1]; var third = somearray[2]; If you use t

1 Basic usage ES6 allows you to define functions using the arrows (=>). var f = v => v; The above arrow function is equivalent to: var f = function (V) {return V; }; If the arrow function requires no arguments or requires more than one argument, a parenthesis is used to represent the parameter portion. var f = () => 5; equivalent to var f = function () {return 5}; var sum = (NUM1, num2) => num1 + num2; equivalent to var sum = function (NUM1, num2)

as follows. function Fibonacci (n) { if (n The tail recursive optimized FIBONACCI sequence is implemented as follows. function Fibonacci2 (n, ac1 = 1, AC2 = 1) { if (n Thus, "Tail call optimization" is significant for recursive operations, so some functional programming languages write it to language specifications. ES6 is so, for the first time explicitly stipulates that all ECMASCRIPT implementations must deploy "tail call optimization". Th

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

Tag: value declares error with same name as module rule more Nan1. Definition of Deconstruction AssignmentIn ES6, it is permissible to extract values (so-called deconstruction) from arrays and objects in a certain pattern, and then assign values to variables.var a = 1; var b = 2; var c = 3; // equivalent to var [A, B, c] = [1, 2, 3];If the deconstruction is unsuccessful, the corresponding variable is assigned a value of undefined.let [x, Y, ... z] = [

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) Why use this design pattern of promise, what are the benefits of this design pattern?The traditional way to solve a JavaScript asynchronous event is to call a callback function, invoke a method, then give it a function reference, and execute the function reference when the method ends.Artifact from Javascript--promisepromise in JS callback function The real problem is that he deprives us of the ability to use return and throw these keywords. And Promise a good solution to all this.

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