javascript oops concepts

: Encapsulates HTML documents into objects, becoming the world's standard in October 1998. The browsers supported by DOM1 include ie6+, Firefox, Safari, Chrome, and opera1.7+.DOM2: Added new features on DOM1, such as resolving namespacesDOM3: Encapsulates an XML document as an objectAll DOM objects in Ps:ie are implemented in the form of COM objects, which means that the DOM in IE may differ somewhat from other browsers.ii. DHTML: Dynamic HTMLis not a language, it is a short term for a number of

A function is a special object;Object: A collection of properties (name-value pairs);The function is used to initialize (with the new operator) a newly created object is called a constructor.The object is called as a method when the property is a function.Within a function body, a local variable takes precedence over a global variable of the same name.code example:varscope = "global"; // Declare a global variablefunctionCheckscope () {varScope = "local";//life a local variable with the same nam

that the value of the object is not null or undefined before using the for-in loop.Label Statement: use the label statement to add tags to your code for future Use.Break and continue with the C language, controlling code execution in the loop body.With statement, The main purpose is to simplify the work of writing the same object multiple Times. (with statement not allowed in strict mode)With (expression) statementvar qs=location.search.substring (1);var hostname=location.hostname;var url=locat

define the scope of the variable.For example, you define a variable at the beginning of a JS file (and outside the function): var first = 1; then this variable first is the local variable of the entire JS document, and the variable is automatically destroyed when the entire document is executed;Again such as:function f () {var first = 1;}Then this variable first is a local variable in the scope of the function f (), and when the function f () is executed, the variable is automatically destroyed

forin expression){ statement; } foreach statement //[ES5] 适合遍历数组,缺点:不能用break跳出循环和用return语句//传统是用for来遍历数组...见仁见智哈var arr = [1,2,3,4];arr.forEach(function(value){console.log(value)})//结果集: 1,2,3,4,undefined for-of statements //[ES6]这货的出现,更加方便了数组的遍历... //它避免了for-in的全部缺陷； //与forEach()不一样，它支持break，continue和return。 var arr = [1,2,3,4]; for(var i of arr){ console.log(i) } //结果集: 1,2,3,4,undefined Label statement //跟goto好相似

JS Case-sensitive　　Label selectors are case-insensitive in HTML/CSS　　ID class selector is case sensitivewhere property Name Property Name property value is not case sensitive　　the case-insensitive content part of the inline event onclick, etc.More than one of the same inline events will be flushed out of the backidentifiers (variables, functions, names of properties)Naming method: The first character must be a letter , an underscore , or a Comment Method　　Single-line comment//Paragraph comment/*

One, JavaScript composition1. A finished javascript is composed of three parts: ECMAScript, DOM, and BOM.ECMAScript: Provides core language functions-grammar, type, statement, keyword, reserved word, operator, object;DOM: Document Object Model-provides methods and interfaces for accessing and manipulating Web page content;BOM: Browser Object Model--provides methods and interfaces for interacting with the br

executeThe return statement can also have no return value, in which case the function returns a undefined value after it has stopped executing. This usage is generally used in cases where the function execution needs to be stopped prematurely without the return value.Arguments object access parameters, Arguments[0]function Doadd (num1,num2) {argument[1]=10;alert (ARGUMENT[0]+NUM2);}ARGUMENT[1] is synchronized with num2, but if the value is passed to a parameter, the value set for argument[1] is

This article is suitable for beginners of JavaScript. Gossip first. In China, there is such a phenomenon: No matter what word or concept, there will always be some people who interpret these things as if they do not understand what they think they are very powerful. In fact, I don't know how many 2. I personally advocate conciseness and clarity. What are the words and concepts? If you can use a short sente

JavaScript code is run in the browser and is written in the tab.JavaScript code can be placed in: 1, head part, 2, body part, 3, external script, encapsulated in the. js file, do not need to write tag.JS syntax Features: 1, Case sensitive, 2, weakly typed language, 3, end with a semicolon, 4, string recommended single quotation marks.Data type: 1, Boolean Boolean type, 2, number digit, 3, string string, 4, undefined undefined, 5, NULL null object, 6

I. Classes and objects1, JavaScript objects fall into three categories: local objects, built-in objects, and host objects.There are 15 types of local objects: Object Function Array String number Boolean Date RegExp Error evalerror rangeerrorRrefenceerror SyntaxError TypeError UirerrorThere are 2 types of built-in objects: Global MathThe host object has N: All DOM and BOM objects2, how to define a class and an object in JavaScriptMethod One: Original m