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1, Deconstruction assignment of array ES6 allows you to extract values from arrays and objects according to a certain pattern and assign values to variables, which is called structure. Previously, assigning values to variables can only be assigned directly; let a =1;let b =2;let c=3; In ES6, it can be written as: let [a,b,c] = [1,2,3]; You c ...

1, First acquaintance with ES6 es6 compatibility view 1. let and const let, like var, is used to declare variables whose values can be changedconst is used to declare constants. Once a constant is initialized, it cannot be re assignedconst must be initialized when declared let name = 'toot toot' let age = 18 const sex = 'female' ...

Master Ajax in an hour Click jump for one hour to master Ajax video Life, one stop has one stop of scenery, one year has one year of taste, your age should be the medal of your life, not the reason for your sadness. What is AJAX? AJAX = Asynchronous JavaScript and XML. AJAX is a technology that can update some web pages without ...

When learning becomes a habit, knowledge becomes common sense. Thank you for your attention, likes, collections and comments.The new video and articles will be sent to WeChat official account for the first time. Li YongningThe article has been included in github warehouse liyongning/blog , welcome to Watch and Star.prefaceAs mentioned earlier, ...

character string includes() console.log('abc'.includes('a'));//true console.log('abc'.includes('ab'));//true console.log('abc'.includes('ac'));//false The second parameter - start search location, which is 0 by default console.log('abc'.includes('a', 0));//true console.log('abc'.includes('a', 1));//false Application - URL add parameters ...

1, What is Axios Axios is a promise based HTTP Library (similar to jQuery's Ajax for HTTP requests)Can be used for browsers and node JS (it can be used for both the client and the server written by node.js) 2, What are the features of Axios Support promise APIIntercept requests and responsesConvert request data and response dataCance ...

Preface: the form verification we talked about this time uses the contents of the previous articles, which is more difficult than the previous ones. I will explain it in detail in the form of comments in the code. catalogue I Simple form validation Verification method 1: Verification method 2: II Regular verification I Regular rules Cont ...

DOM event flow To understand the event flow, we must first understand three points: Elements are not independent, they are connected in seriesAfter a single element triggers an event, it will affect other elementsMode of event flow: event capture (proposed by Netscape) and event bubbling (proposed by IE) Let's take the above figure as ...

Prototype inheritance Advantages: the same prototype object Disadvantages: the prototype object cannot be modified, which will affect all instances function Animal(){ this.type = "animal" }; function Cat(name,color){ this.name = name; this.color = color; }; Cat.prototype = new Animal ...

10. Database and identity authentication 1. Steps to operate the database in the project Install the third-party module (MySQL) that operates the MySQL databaseConnect to MYSQL database through MYSQL moduleExecute SQL statements through mysql module 2. The code realizes the connection to the database //1. Import mysql module //import mysql ...