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The try-catch Statement try{ window.someFunction(); }catch(error) { alert(error.message); } The finally Clause: function testFinally(){ try { return 2; } catch (error){ return 1; } finally { retu...
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Using contenteditable <div class=”editable” id=”richedit” contenteditable></div> Rich Text Selections getSelection(); Rich Text in Forms EventUtil.addHandler(form, “submit”, funct...
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➤ Field names and values are URL-encoded and delimited using an ampersand. ➤ Disabled fields aren’t sent at all. ➤ A check box or radio field is sent only if it is checked. ➤ Butto...
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<select> and <option> HTMLSelectElement，HTMLOptionElement add(newOption, relOption) — Adds a new <option> element to the control before the related option. multiple — A Boolean...
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<input type=”text” size=”25” maxlength=”50” value=”initial value”> <textarea rows=”25” cols=”5”>initial value</textarea> var textbox = document.forms[0].elements[“tex...
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FORM BASICS HTMLFormElement acceptCharset — The character sets that the server can process; equivalent to the HTML accept-charset attribute. action — The URL to send the request to; equivalent to...
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Event Delegation <ul id=”myLinks”> <li id=”goSomewhere”>Go somewhere</li> <li id=”doSomething”>Do something</li> <li id=”sayHi”>Say hi</li> </ul...
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click — Fires when the user clicks the primary mouse button (typically the left button) or when the user presses the Enter key. dblclick — Fires when the user double-clicks the primary mouse butt...
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Focus events are fi red when elements of a page receive or lose focus. document.hasFocus() and document.activeElement blur — Fires when an element has lost focus. This event does not bubble and...
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User interface (UI) events are general browser events that may have some interaction with the BOM. Focus events are fired when an element gains or loses focus. Mouse events are fired when the m...
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This object contains basic information such as the element that caused the event, the type of event that occurred, and any other data that may be relevant to the particular event. The DOM Event Obj...
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HTML Event Handlers' <input type=”button” value=”Click Me” onclick=”alert(‘Clicked’)” /> <input type=”button” value=”Click Me” onclick=”alert("Clicked")” /&...
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var supportsDOM2StyleSheets = document.implementation.hasFeature(“StyleSheets”, “2.0”); disabled — A Boolean value indicating if the style sheet is disabled. href — The URL ...
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cssText — As described previously, provides access to the CSS code of the style ttribute. length — The number of CSS properties applied to the element. parentRule — The CSSRule object representi...
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The <table> element adds the following: caption — Pointer to the <caption> element (if it exists). tBodies — An HTMLCollection of <tbody> elements. tFoot — Pointer to the <t...
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加载样式文件： function loadStyles(url){ var link = document.createElement(“link”); link.rel = “stylesheet”; link.type = “text/css”; link.href = url; var head = document.getElementsByTagName(...
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external JavaScript file: function loadScript(url){ var script = document.createElement(“script”); script.type = “text/javascript”; script.src = url; document.body.appendChild(script); } load...
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nodeType is 3. nodeName is “#text”. nodeValue is text contained in the node. parentNode is an Element. Child nodes are not supported. appendData(text) — Appends text to the end of the node. dele...
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nodeType is 1. nodeName is the element’s tag name. nodeValue is null. parentNode may be a Document or Element. Child nodes may be Element, Text, Comment, ProcessingInstruction, CDATASection, or En...
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nodeType is 9. nodeName is “#document”. nodeValue is null. parentNode is null. ownerDocument is null. Child nodes may be a DocumentType (maximum of one), Element (maximum of one), ProcessingInstr...
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The Node Type Node.ELEMENT_NODE (1) Node.ATTRIBUTE_NODE (2) Node.TEXT_NODE (3) Node.CDATA_SECTION_NODE (4) Node.ENTITY_REFERENCE_NODE (5) Node.ENTITY_NODE (6) Node.PROCESSING_INSTRUCTION_NODE (7) N...
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The Complete Script var client = function(){ //rendering engines var engine = { ie: 0, gecko: 0, webkit: 0, khtml: 0, opera: 0, //complete version ver: null }; //browsers var browser = { //browsers...
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能力检测：比如判断是否支持函数：document.getElementById function getElement(id){ if (document.getElementById){ return document.getElementById(id); } else if (document.all){ return document.all[id];...
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window.resizeTo(screen.availWidth, screen.availHeight); THE HISTORY OBJECT Because history is a property of window, each browser window, tab, and frame has its own history object relating specifi...
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浏览器属性： Detecting Plug-ins 查找插件,插件属性： name description filename length 比如： //plugin detection - doesn’t work in Internet Explorer function hasPlugin(name){ name = name.toLowerCase...
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window.location & document.location 指向同一个对象 属性： hash "#content" host " http://www.byhard.com:80 " hostname " http://www.byhard.com " href ...
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alert(); confirm();返回boolean值，点击ok（确定）的返回true, cancel（取消）返回false。 if(confirm("Are you sure")) { alert("I am glad."); } else { alert("I am sorry."); } prompt();让用户输入数据参数...
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setTimeout()表示指定的毫秒数后调用函数或计算表达式，相当于定时任务。 两个参数：1执行的代码段，2，执行代码前所等待的时间（毫秒）； //avoid! setTimeout(“alert(‘Hello world!’) “, 1000); //preferre...
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window.open(); 四个参数： the URL to load, the window target, a string of features, and a Boolean value indicating that the new page should take the place of the currently loaded page in the browse...
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var leftPos = (typeof window.screenLeft == “number”) ? window.screenLeft : window.screenX; var topPos = (typeof window.screenTop == “number”) ? window.screenTop : window.screenY; //move the win...
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var age = 29; function sayAge(){ alert(this.age); } alert(window.age); //29 sayAge(); //29 window.sayAge(); //29 global变量不能通过delete删除： var age = 29; window.color = “re...
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sayHi(); //error – function doesn’t exist yet var sayHi = function(){ alert(“Hi!”); }; 条件声明函数： //this is okay var sayHi; if(condition){ sayHi = function(){ alert(“Hi!”); }; } else {...
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The Factory Pattern function createPerson(name, age, job){ var o = new Object(); o.name = name; o.age = age; o.job = job; o.sayName = function(){ alert(this.name); }; return o; } var person1 = crea...
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ECMAScript objects as hash tables: nothing more than a grouping of name-value pairs where the value may be data or a function. var person = new Object(); person.name = “Nicholas”; person.age = 29...
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The Math Object The min() and max() Methods var max = Math.max(3, 54, 32, 16); alert(max); //54 var min = Math.min(3, 54, 32, 16); alert(min); //3 var values = [1, 2, 3, 4, 5, 6, 7, 8]; var m...
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The Global Object URI-Encoding Methods encodeURI() & encodeURIComponent() 比如： var uri = “ http://www.wrox.com/illegal value.htm#start”; //” http://www.wrox.com/illegal%20value.htm#start...
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原类型对应的引用类型：Boolean, Number, String. Three special reference types are designed to ease interaction with primitive values: the Boolean type, the Number type, and the String type. var s1 =...
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Function Internals Two special objects exist inside a function: arguments and this. the arguments object also has a property named callee, which is a pointer to the function that owns the arguments...
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js中函数实际上是object. Each function is an instance of the Function type that has properties and methods just like any other reference type. Because functions are objects, function names are simpl...
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RegExp Constructor Properties input $_ lastMatch $& lastParen $+ leftContext $` multiline $* rightContext $’ var text = “this has been a short summer”; var pattern = /(.)hort/g; /* * Note: O...
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RegExp Instance Methods var text = “mom and dad and baby”; var pattern = /mom( and dad( and baby)?)?/gi; var matches = pattern.exec(text); alert(matches.index); //0 alert(matches.input); //...
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var expression = /pattern/flags; The pattern part of the expression can be any simple or complicated regular expression, including character classes, quantifiers, grouping, lookaheads, and backre...
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var now = new Date(); Date.parse(); Date.UTC(); Date.parse()接受下面的时间格式： month/date/year (such as 6/13/2004) month_name date, year (such as January 12, 2004) day_of_week month_name date yea...
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Reduction Methods var values = [1,2,3,4,5]; var sum = values.reduce(function(prev, cur, index, array){ return prev + cur; }); alert(sum); //15 var values = [1,2,3,4,5]; var sum = values.reduceRight...
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Location Methods indexOf(), lastIndexOf(); 两个方法都可以接受两个参数，第一个参数表示要查找的元素，第二个可选参数，表示从哪里开始查找。indexOf()表示从前往后找，lastIndexOf()表示从后往前找。如果都未...
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Stack Methods 堆栈方法 后入先出（lifo），堆栈操作。pop, push是Array自带的方法。 var colors = new Array(); //create an array var count = colors.push(“red”, “green”); /...
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js中的array是有序数组，可以存储任何类型的数据。 数组创建： var colors = new Array(); 如果知道数组长度： var colors = new Array(20); 也可直接定义数组元素进行创建： var colors = new Array(“red”, “...
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var person = new Object(); person.name = “Nicholas”; person.age = 29; object literal notation: var person = { name : “Nicholas”, age : 29 }; 这样写也允许的： var person = { “name” : “Nichola...
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Mark-and-Sweep 未标记表示变量在上下文中被引用，如果仍是标记的，表示准备删除的变量。 Reference Counting 引用计数，如果引用计数数量为0，表示变量无法被访问，可以被删除。 但会碰到循环引用的问题。 Perfo...
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var color = “blue”; function changeColor(){ if (color === “blue”){ color = “red”; } else { color = “blue”; } } changeColor(); Scope Chain Augmentation The catch block in a try-catch stateme...
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Five primitive types:Undefined, Null, Boolean, Number, and String. 能过值访问。 Reference values are objects stored in memory. 与其它编程语言不同，js不允许直接访问内存，事实上访问的是对象的引用，...
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Strict mode places several restrictions on functions: No function can be named eval or arguments. No named parameter can be named eval or arguments. No two named parameters can have the same name. ...
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The if Statement The do-while Statement The while Statement The for Statement for (;;) { //infinite loop doSomething(); } The for-in Statement for (property in expression) statement fo...
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Equal and Not Equal EXPRESSION VALUE null == undefined true “NaN” == NaN false 5 == NaN false NaN == NaN false NaN != NaN true false == 0 true true == 1 true true == 2 false undefined == 0 false ...
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Multiplicative Operators 如数值类型的变量，需隐式转换成数值类型，使用Number()转换函数。 Multiply If the operands are numbers, regular arithmetic multiplication is performed, meaning that two positi...
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Unary Operators ++,-- ➤ When used on a string that is a valid representation of a number, convert to a number and apply the change. The variable is changed from a string to a number. ➤ When u...
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Character Literals var text="\u03a3"; alert(text.length) //1 Converting to a String var age = 11; var ageAsString = age.toString(); //the string “11” var found = true; var foundAsString = foun...
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Number Conversions Number() //can be used on any data type; parseInt() //converting strings to numbers. parseFloat() //converting strings to numbers. var num1 = Number(“Hello world!”); //...
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The Number Type 0开头表示八进制，如果解析不正确，会默认成10进制数。比如： var octalNum1 = 070; //octal for 56 var octalNum2 = 079; //invalid octal - interpreted as 79 var octalNum3 = 08; ...
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The typeof Operator Note that because typeof is an operator and not a function, no parentheses are required (although they can be used). The Undefined Type var message; alert(message == undefined...
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Keywords: break do instanceof typeof case else new var catch finally return void continue ...
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Case-sensitivity Identifiers The first character must be a letter, an underscore (_), or a dollar sign ($). All other characters may be letters, underscores, dollar signs, or numbers. Strict Mo...
