documentall[]详解.docVIP

1、理解document.all[] 从IE4开始IE的object model才增加了document.all[],来看看document.all[]的Description: Array of all HTML tags in the document.Collection of all elements contained by the object. 也就是说document.all[]是文档中所有标签组成的一个数组变量，包括了文档对象中所有元素（见例1）。 IE’s document.all collection exposes all document elements.This array provides access to every element in the document. document.all[]这个数组可以访问文档中所有元素。 例1（这个可以让你理解文档中哪些是对象） !DOCTYPE html PUBLIC -//W3C//DTD XHTML 1.0 Transitional//EN  HYPERLINK /TR/xhtml1/DTD/xhtml1-transitional.dtd \t _blank /TR/xhtml1/DTD/xhtml1-transitional.dtd html xmlns= HYPERLINK /1999/xhtml \t _blank /1999/xhtml head titleDocument.All Example/title meta http-equiv=content-type content=text/html; charset=ISO-8859-1 / /head body h1Example Heading/h1 hr / pThis is a emparagraph/em. It is only a emparagraph./em/p pYet another emparagraph./em/p pThis final emparagraph/em has em id=specialspecial emphasis./em/p hr / script type=text/javascript !-- var i,origLength; origLength = document.all.length; document.write(document.all.length=+origLength+br /); for (i = 0; i origLength; i++) { document.write(document.all[+i+]=+document.all[i].tagName+br /); } //-- /script /body /html 输出结果： Example Heading -------------------------------------------------------------------------------- This is a paragraph. It is only a paragraph. Yet another paragraph. This final paragraph has special emphasis. -------------------------------------------------------------------------------- document.all.length=272 document.all[0]=! document.all[1]=HTML document.all[2]=HEAD document.all[3]=TITLE document.all[4]=META document.all[5]=META document.all[6]=META document.all[7]=LINK document.all[8]=LINK document.all[9]=SCRIPT document.all[10]=SCRIPT document.all[11]=BODY document.all[12]=CENTER document.all[13]=! document.all[14]=DIV document.all[15]=UL document.all[16]=LI document.all[17]=A document.all[18]=FONT document.all[19]=A document.all[20]=FONT document.all[21]=LI document.