JavaScript

//The same element-level attribute is encountered, whichever is (minor)//does not return the new object, but main changes functionMergejson (minor, main) { for(varKeyinchminor) { if(Main[key] = = = undefined)

Single topic Class= "FL" >0 questions available Value= "" placeholder= "0" > Fill in the Blanks Class= "FL" >0 questions available Value= "" placeholder= "0" > Computational questions Class= "FL" >0 questions available Value= "" placeholder= "0"

The event handlers in JavaScript are divided into 3 main types: HTML Event Handlers: click me! DOM0-level Event handlers:　　 click me! DOM2-level Event handlers: click me! Attach the Compatibility

JavaScript is a vibrant, easy-to-use language and a language with many complex and subtle techniques. The paradox of JavaScript is that even experienced JavaScript developers don't really understand them if they don't study hard. Because JavaScript

Returns the prototype of the object.GrammarObject.getprototypeof (object)ParametersObjectNecessary. the object that references the prototype. return valueobject argument.">The prototype of the object parameter. prototypes are also objects.

An absolute value less than or equal to 2 of the 53-square integer, that is-253 to 253, can be precisely represented, that is, the 15-bit decimal number can be accurately processed ; JavaScript can represent a range of values from 21024 to 2-1023 (

In the browser of IE kernel, the following code supportsdocument.all (i). Tagname.tolowercase ();However, in Firefox, the above code is not supported, so you need to use the following line of code instead of the above

Gets the check box element to the checkbox by the ID of the check box to bind the point-to-click eventEach checkbox is set to the same name CheckoneGet the status of a checkbox by the resulting elementWhen clicking Select All Uncheck CheckBox, check

Code:/*@desc：表格排序类@param data 待排序数组*/function tablesort(data){this.data = datathis.sortby = true/* @desc：主方法，排序 @param item 排序字段 @return ret 排序后的数据 */this.sort = function(item){ if(this.sortby){ var ret = this.data.sort(function(a,b){

The filter () method creates a new array that contains all the elements tested by the callback function.Const WORDS = [' spray ', ' limit ', ' elite ', ' exuberant ', ' destruction ', ' present '];Const RESULT = Words.filter (Word = word.length > 6);

Knowledge points to use:Get table elementsTbody and rows are indexed.Here we have only one set of tbody so the index is 0Even row index takes 2 to 0Odd row index takes 2 less than 0Set the appropriate color by traversing the row index. table

1, introduce the basic data type JSUndefined, Null, Boolean, number, String2. What are the built-in objects of JS?Data encapsulation Class object: Object, Array, Boolean, number, and StringOther objects: Function, Arguments, Math, Date, REGEXP,

this keywordThe This keyword is typically used inside a function or inside an object.The location of a function or method declaration affects the meaning of the This keyword.Typically, this points to the object that the current function is

1 Concepts of objectsA: Object is an abstraction of a single substanceB: The object is a container that encapsulates properties and methods2 constructorsThe first step in object-oriented programming is to generate objects. Object-oriented

Use of anonymous functionscreateTextNode Creating textCreateElement Creating elementsAppendChild to append text or elements dynamic Add City < UL id= "UL1" > Beijing Shanghai Guangzhou JavaScript adds cities dynamically

Example/*/*function need to be marked with * yiled can return multiple values */function* calculate (A, b) { yield a + b; Yield A + A; Throw ' some error '//encountered an error immediately return, so the following code will not be executed

The "javascript:" Pseudo-Protocol is a non-standardized protocol that allows us to invoke JavaScript functions through a link. For example: ExampleHowever, there are some problems, that is, this form can be used in browsers that support

Generally for different enterprises with their own packaged front-end Custom Function moduleBaidu, Yahoo and other large enterprises have their own package of single-case modeThe following is mainly about the three modules of the singleton model:

In the development process, JS native events are not enough to satisfy the development requirements, developers need to customize the event.First, the EventThe event () constructor creates a new event.New Event (Typearg,eventinit);TypeargThe event

Regular expressions are typically used for two string methods:The search () method retrieves the string specified in the string, or retrieves a substring that matches the regular expression and returns the starting position of the substring.The