eloquent javascript second edition

functions in other languages: You do not need to specify a function's return value, because any ECMAScript function can return any value at any time. In fact, a function that does not specify a return value returns a special undefined value. There is also no concept of a function signature in ECMAScript, because its function parameters are passed in a form of an array of 0 or more values. You can pass any number of arguments to the ECMAScript function, and you can access th

handle keyboard events, and pressing any key on the keyboard triggers the onkeypress event. In some browsers, even the TAB key is included.In almost all browsers, using the TAB key to move to a link and press ENTER will also trigger the OnClick event.Five. DOM Core and Html-dom:1. Dom Core: Not specifically for JS, any programming language that supports the DOM can use them. The use is not limited to processing Web pages, they can be used to process documents written in any one markup language,

larger when the unsigned right shifts >>>23.nan/null/undefined participate in operations, return to themselves; Engage with oneself | | The operation returns itself;24.Infinity * 0 =nan,*-num=-infinity,*+num=infinity;25.0/0=nan,2/0=infinity,-2/0=-infinity26.0%num=0,num%infinity (-infinity) =num,infinity%num=nan,infinity%num=nan;27.Infinity +-infinity = NaN28. Uppercase letters are encoded less than lowercase29.== conversion type in comparison, = = = does not convert (including comparison data

Bubble sortfunctionbubblesort (arr) {varLen =arr.length; for(vari = 0; I ) { for(varj = 0; J ) { if(arr[j] > Arr[j+1]) {//adjacent elements 22 contrast vartemp = arr[j+1];//element Exchangearr[j+1] =arr[j]; arr[j]=temp; } } } returnarr;}Select sortfunctionselectionsort (arr) {varLen =arr.length; varminindex, temp; for(vari = 0; I ) {minindex=i; for(varj = i + 1; J ) { if(arr[j] //Find the smallest numberMinindex = j;//Save the index of

name of the attribute. For example, to add the align attribute to an element, you can use the following code:var attr = Document.createattribute ("align"); Attr.value = "Left"; Element.setattributenode (attr); alert ( element.attributes["Align"].value); "Left" alert (Element.getattributenode ("Align"). Value); "Left" alert (Element.getattribute ("align")); "Left"Run for a minuteThis example creates a new feature node. Since the Name property has been assigned a value when calling CreateAttribut

2017-05-10JS IntroductionInvented by a man named "Not hard to be". The popularity of JS is due to the relationship between Ajax.JS is divided into three parts: Core: ECMAScript Document Object Model: DOM Browser Object Model: BOM Core: ECMAScriptHe has nothing to do with the browser, just the syntax, the type, the keywords or something.Document Object Model: DOMDom is to think of HTML as a tree structure so that you can manipulate them through the API.Html:html> head> t

value (or pointer), the reference point to the object is not involved in replication, That means the last two reference variables point to the same object5. Each execution environment has a variable object associated with it, and all variables and functions defined in the environment are stored in the object. There are many kinds of execution environment, such as global environment, function environment, with environment, and so on, the variable objects of these environments form the scope chai

Compares the adjacent elements. If the first one is bigger than the second one, swap them both.Do the same for each pair of adjacent elements, starting with the last pair from the first pair to the end. At this point, the last element should be the maximum number.Repeat the above steps for all elements, except for the last one.Repeat the above steps each time for fewer elements, until there are no pairs of numbers to compare.functionsort (elements) { for(vari=0;i){ for(varj=0;j){ if(ele

value of the split position, the latter sequence is larger than the value of the split position varpartitionpos=partition (elements, low, high); //continuation of recursive ordering of previous sequencesSort (elements, 0, partitionPos-1); //continuation of recursive ordering of post sequencesSort (Elements, partitionpos+1, high); }}varelements = [3, 1, 5, 7, 2, 4, 9, 6, 10, 8];console.log (' Before: ' +elements); sort (elements,0, Elements.length-1); Console.log (' After: ' + elements);Effic

PDF version, English version 158th page,var IsArray = Function.isarray | | Function (o) {return typeof o = = = = "Object" object.prototype.tostring.call (o) = = = "[Object Array]";}; return typeof o = = = "Object" object.prototype.tostring.call (o) = = = "[Object Array]";};Array.isarray is a function provided by ES5, this example is to implement this function in ES3, first, if the browser supports Array.isarray, it is assigned to IsArray, otherwise the subsequent function is assigned to IsArray.

suffix "json";3) Fix the bug that the toolbar "run" or "stop" button will not change while switching the active document;4) Fixed bug where the status bar information at the bottom of the IDE does not change with the toggle active document.2, 1.0.0.4 (Ejstool Alpha2 v1.0[r5.1]) "February 26, 2015":1) Remove the Datetime.ejs file from the runtime (Lib) directory and remove the Datetime.ejs reference within the __init__.ejs file;2) Later, you cannot directly use the new Date (). Format date (This

The Style property is an object and can only return inline styles.When you need to reference a CSS property with a minus sign in the middle, the DOM asks for the hump naming method, that is, the CSS property font-family becomes the DOM attribute fontFamliy:element.style.fontFamilyRegardless of the number of hyphens in the CSS style attribute's name, the DOM is all represented by the Hump naming method, which is the CSS property backg-color corresponding to the DOM attribute backgroundcolor.CSS3

content "Hello world" is created.InsertBefore: Insert a new element in front of an existing element, when calling this method, you must know three things: 1, new element: The element you want to insert (newelement) 2, Target element: Before which element (targetelement) you want to insert this new element 3, parent element: The parent element of the target element (parentelement) Syntax: Patentelement.insertbefore (newelement,targetelement) We don't have to figure out what the parent element is

array. This method has no return value. Map (): Each item in the array is a given function that returns an array of the results of each function call. Some (): Runs the given function for each item in the array, and returns True if the function returns true for either item. 1 var numbers = [1,2,3,4,5,4,3,2,1];2 3 var everyresult = numbers.every (function (item, index, array) {4 return (item > 2);5 });6 7 alert (Everyresult); False8 9 var someresult = num

Web authoring from getting started to mastering catalogs:1th Chapter HTML Basics2nd Chapter HTML Basic Markup3rd Chapter text and paragraph markThe 4th chapter uses the image5th Use ListThe 6th chapter uses the form7th Chapter Set up hyperlinks8th Chapter Add MultimediaThe 9th chapter uses the framework structureChapter 10th using FormsThe 11th chapter uses XHTMLThe 12th chapter uses CSS style sheets13th Web Standard and CSS page layout example14th Chapter Script BasicsThe 15th chapter uses the

best-selling Ajax advanced programming.[1]Directory editing 1th chapter JavaScript What is 1.1 history brief 1.2 JavaScript Implementation 1.3 Summary 2nd Chapter ECMAScript Foundation. 2.1 Syntax 2.2 variable 2.3 keyword 2.4 reserved word 2.5 original value and reference value 2.6 original Type 2.7 Conversion 2.8 Reference type 2.9 operator 2.10 Statement 2.11 Function 2.12 Summary 3rd Object Foundation 3

, mainly think that this is a javascript of some of the custom functions, should be encapsulated in the function library. It also defines the static variable plugininfo, which declares some basic information about the class library using static variables.Below is a description of the functions in a library:First, declare the function name Checkbrowser, encapsulating it with function anonymous functions. Add a function declaration comment below the {nu

adept at handling repetitive tasks. It is easy to traverse a long list with a while or for loop.Responding to EventsCSS provides: pseudo-class attributes such as hover allow us to change the style based on the state of the HTML element. The DOM can also respond to changes in the state of an HTML element through events such as onmouseover. So when to use: hover, when to use onmouseover?The simplest answer is to choose the easiest way to achieve it. For example, if you just want the link to chang