JavaScript

Factory creates objects by providing a common interface, and we can also specify the type of object instances we want to create.Suppose you now have a car factory vehiclefactory, which supports the creation of object instances of car and truck types

JavaScript was born in 1995, when its main purpose was to handle input validation operations (the frequent exchange of data with a server without completing simple forms validation would only add to the burden on the user). Before the advent of

JavaScript Basic Learning (ii) Instanceof method: vars = "Hello"; vari = 8; //typeof can only judge basic data typesAlerttypeof(s)); Alert (typeof(i)); //for reference data types, use the instanceof varS2=NewString ("Hello2") Alert

"15" ES6 for humansTotal 148 page: Now see: Read all.Amazon Address:Konjac: summary: I first looked at Ruan Yi Feng's online books. Many of the contents of the book are repeated. Actually sells ￥463. And no one else. are basic concepts. Add some

?? In JavaScript the function is a one-class citizen . The so-called one-class citizen refers to functions like other objects, very common, can be in the array of functions exist, as parameters passed, assigned to variables and other operations.

Date Object and Time objectDate object is used for manipulating datesTime object for Operation TimesThe date object needs to be instantiated before it is used, and instantiated with a constructor function.var today=new Date ();//

String object. Number object. Math ObjectString ObjectThe properties and methods of a string object are used to manipulate strings.html lang="en">head>    meta charset="UTF-8">    title>Titletitle>head>body>script>var str="I like javascript

Params.query = Params.query.replace (/[\+\-\&\|\!\ (\) \{\}\[\]\^\ "\~\*\?\:\\]/g,function(a) {Switch(a) { Case+: return' \\+ ' Break; Case‘-‘: return‘\\-‘ Break; Case' & ': return' \\& ' Break; Case|:

JavaScript Code Exception MonitoringJavaScript exceptions generally have two aspects: syntax errors and run-time errors. The methods of capturing and processing two kinds of errors are different, which can affect the specific scheme selection. In

JavaScript BOM object JavaScript Window-Browser object modelThe browser object Model (BOM) gives JavaScript the ability to "talk" to the browser.Browser object Model (BOM)There is no formal standard for the browser object model (Browser object Model:

Original: https://www.cnblogs.com/codernie/p/9098184.html--------------------------------------------------------------------------------1. What is the prototype of the class???? In JavaScript, whenever we define a constructor, the JavaScript engine

1. getElementByIddocument.getElementById ("Id_value") # return value is a node object, when no element is returned = = = undefined Value (two equals sign)2. GetelementsbynameDocument.getelementsbyname ("Name_value") # Returns a value of NodeList

CycleUsing for 1 * 2 * 3 * ... * 10 The results of a cyclic calculation:' Use strict '; var x = 1; var i; for (i=1;i) {x=x*i;} if (x = = 3628800) { console.log (' 1 x 2 x 3 x ... x = ' + x ' );} Else { console.log (' calculation error

What is a JavaScript variable promotion?--When the JS program runs,(a) The declaration of a variable is "lifted" by the interpreter to the top of the body of the method, and the initialization assignment operation is not promoted sequentially(b) An

native Simple Magnifier of JavaScript instancesMagnifier Effect Analysis:One, Tab effectMouse move into a small chart list of one of the pictures, small picture border effect, large box appears corresponding large mapSecond, Magnifier effectMouse

In the application of JavaScript, it is often encountered to determine whether two objects/values are equal. Some indicate that they look the same, but they are not the same. There are some special cases that we need to identify.Reference typeThey

A total of six types of data in JS:Five types of value: Boolea number String Null undefinedReference type: Object----Three major reference types: Object Array FunctionTopic 1:var A = 100;var B = A;A = 200;Console.log (b);Topic 2:var A = {age:20};var

Expressions and operatorsAn expressionAn expression can ask for a value, and the evaluation can contain an operation.varlength=80Two or more values can be used in an expression, and the expression eventually returns a value. If you ask for the area

JavaScript cross-domain communicationHomologous: Two documents of the same origin need to meet Same protocol Same domain name Same port cross-domain communication methods:01, by settingimg,script,link,iframe ElementsThe

One, load and runJavaScript code execution blocks other browser processes, leverages Webpack or Gulp tools to compress files, reduces the number of JS files, and thus reduces the number of HTTP requests to improve the actual performance of Web