JavaScript

I. null 1. It is generally regarded as a special value of the object type, that is, the value of "no object; 2. if it is used in a Boolean environment, it is converted to false, the numeric environment is 0, and the string environment is "null ";

Javascript verification form List, using JS Control Form submission, JavaScript submit form Directory: 1: limit on the length of JavaScript strings, determine the length of characters, restrict input by JS, restrict input by restriction, and limit

In this chapter, I will give an overview of important events, including compatibility issues with some popular browsers.The events proposed here, when they happen on a fixed HTML element, their names can be recognized by most browsers. That is to

In the first chapter, I mentioned a problem that may not seem so understandable for the first time: "If an element and its parent element have event processing for the same eventProgramWhich of the following statements will be executed first ?"

1. instance attributes, instance methods and class attributes, and class methods Function circle (r ){ This. redius = r; // redius attribute instance attributes, that is, each instance object of this type has the copy

In JavaScript, void is an operator that specifies to calculate an expression but does not return a value. The format of the void operator is as follows: 1. javascript: void (expression) 2. javascript: void expressionexpression is a standard

The rectangle () function is used as an example. 1. Simple Functions Function rectangle (W, h ){ This. width = W; This. Height = h; } VaR test = new rectangle (); create a simple rectangle object,

Use a regular expression to determine whether it is a 0-9 Arabic number function regisdigit (fdata) { var Reg = new Regexp ("^ [0-9] $"); return (Reg. test (fdata); } use this expression to obtain the string length function regdatalength (fdata)

Closure is a difficult and characteristic of JavaScript language. Many advanced applications rely on closures for implementation. The following are my study notes, which are useful for beginners of JavaScript. I. Scope of Variables To understand

In XSL, JavaScript and other scripting languages can be used, but XML specifications must be followed. Therefore, use . For example, you can use the next XSL to implement screen scrolling:    

Eval in Javascript    First, let's give a simple understanding. Eval can execute the string generation Statement, which is similar to SQL exec.What is the use of eval?

Http://alert-mm.iteye.com/blog/205275 Use IFRAME and pop-up sub-page to refresh the IFRAME of the parent pageJS Code Pop-up subpageJS Code Child Window refresh parent windowJS Code Refresh the window opened in the open ()

In the latest system, you need to pop up a small window on the interface, just like the following: Obviously. Net cannot be used, and JS is required. It is said that JS produces various cool effects. As a result, I wrote some code and also

Excerpt: Scope of variables in Javascript   TheScopeOf a variable is all parts of a program where it is visible. Being visible means that the variable has been declared and is available for use. A variable that is visible everywhere in the program

1. How to use this: This indicates the object of the current function. The following demo provides a brief description: Function dosomething (){Alert (this );}Dosomething (); I am debugging in Firefox, so the returned result is [Object window].So

Base64Is a representation of binary data based on 64 printable characters. Because the power of 6 in 2 is equal to 64, every 6 bits are a unit and correspond to a printable character. The three bytes have 24 BITs, which correspond to four base64

Supported by the second-generation browser. These old browsers only support one method to register the event handler, Which is Netscape . Because Netscape is preemptive, if Microsoft wants to browse JavaScript events So there is no compatibility

Because javascript can process interaction with users, using JavaScript provides a better user experience. In this article, you can see some horrible and unique navigation bars produced by JavaScript.1. menumaticThis example shows a vertical or

1.doc ument. write (""); Output Statement 2. the comments in JS are // 3. the traditional HTML document sequence is: Document-> HTML-> (Head, body) 4. the Dom sequence in a browser window is: window-> (navigator, screen, history, location, document)

1. prototype and [[prototype] Prototype usually represents two concepts. The constructor has a common prototype attribute. When the constructor is used to create a new object, a [[prototype] attribute is used as a reference to the prototype