JavaScript

NumberJavaScript does not distinguish between integers and floating-point numbers, and is uniformly represented by number, and the following are valid number types:// Integer 123 // floating point 0.456 // scientific notation means 1.2345x1000,

Scope 1. Global EnvironmentWINDOW:JS Global execution Environment, top-level object. The this pointer points to window when the global execution environment is executed.console.log(this===window); //true2. Local EnvironmentWhat situation will have a

I. How JavaScript is introduced1. In the script tag: 2. Introduction of external JS file: Two. JavaScript Language specification1. Note: ①.//single-line comment②./* Multiline Comment */2. Terminator: The statements in JavaScript are separated by

/* * * Step1: * Result: 1, ' 2 ' */= { 1, ' 2 ' } Let { num, str = opt; console.log (num, str); // ####################################### // reminds me of the way I used to be assigned. Let obj

DOCTYPE HTML>HTML> Head> MetaCharSet= "Utf-8" /> Metaname= "Viewport"content= "Width=device-width, initial-scale=1"> title>The window in JavaScripttitle> Window Learning 1.Window Common Method dialog box alert---Pop-up

1. Debugging JavaScriptDebug JavaScript with Chrome browser developer tools.In Chrome, choose the menu item "More Tools"-"Developer Tools", open the Developer toolbar, shortcut keys "F12" or "ctrl+shift+i",Selecting the Console,console window in the

' | | ' and ' && ' are common logical operatorsBut I did not expect in the JavaScript grammar world can also use them to play a trick, as a Java programmer of my face, especially on the Internet to check some, hereby record:&&: Before and after, if

Queryselect () This is relatively straightforward and straightforward, and can be understood in a few examplesGets the first element of class= "example" in the Document: Document.queryselector (". Example"); P > element: Document.queryselector ("P");

One, what is the sort of hillThe Hill sort (Shell's sort) is a more efficient and improved version of the Insert Sort algorithm, also known as "narrowing incremental sorting".   Ideas:     Hill sort is to group records by a certain increment of the

First, how to create a function1) Normal wayfunction cal (NUM1, num2) { return num1+num2; }2) Use of variable initialization methodvar function (NUM1, num2) { + num2);} // Plus (15,20);3) using constructors// This method is deprecated, and

Garbage collection It's all about collecting things that are already unused, cleaning them up, and releasing the space they occupy.JavaScript has an automatic garbage collection mechanism, which means that we don't have to think about memory when we'

Introducing two browsers:Chrome:1. Open the Chrome extensions page-chrome://extensions2. Save the custom script you just made as a. js file with user.js suffix, such as test.user.js, and drag it into the Extensions page.3. Restart the browser.4. Go

　　　　 //1: Based on ID//var element = document.getElementById ("test");Console.log (element);//2: Based on classvar elements = document.getelementsbyclassname ("Clazz");For (var index in elements) { //Console.log (Elements[index]);

First, double traverse to go heavyfunction Onlyfigure (arr) {let newarr = []; Const LENGTH = Arr.length for (Let i = 0; i 　　Second, the original array subscript indexof to the weightfunction Onlyfigure (arr) {let newarr = [];

DOCTYPE HTML>HTMLLang= "en">Head> MetaCharSet= "UTF-8"> title>Titletitle> Scriptsrc= "Common.js">Script> Script> /** Offset Series: Gets the element's width, height, left,top, offsetParent * offsetwidth: The width of the element,

The author of this series is Kyle Simpson, volume translator Shano, Matthew, Tan Ye, the translator Tan Ye, Jiangnan.I personally feel that the first volume is the best of this series (must read), while the second volume, although also explained a

Object Search Algorithm Challengefunctionwhere (collection, source) {vararr = [];varStatus =NULL;//What's in a name? for(vari = 0; i ) { for(varImpinchsource) { if(Source[imp]!==Collection[i][imp]) {Status= 0; Break; } Status= 1; } if(

online?-www.51windows. Net When I disabled the network card while surfing the Internet, I checked it offline in about four seconds !!, An online error is detected about 8 seconds after the NIC is enabled !!!  

Function getparameter (varname){VaR query = location. search;If (query! = NULL | query! = ""){Query = query. Replace (/^ /? + /,"");VaR qarray = query. Split ("&");VaR Len = qarray. length;If (LEN> 0){For (VAR I = 0; I {VaR sarray = qarray [I].

Two Methods of addition operation written in JavascriptCode: demo01.html --> - -->