南强小屋 Design By 杰米
于是就测试了下：
复制代码 代码如下:
var stringToDom=function(text) {
var doc;
if(window.ActiveXObject) {
doc = new ActiveXObject("MSXML2.DOMDocument");
doc.loadXML(text).documentElement;
} else {
doc = (new DOMParser()).parseFromString(text,"text/xml");
}
return doc;
}
var xmlDoc=stringToDom("<body><a href='a'>a</a><a href='b'>b</a></body>"),
c,
d1=new Date();
for(var i=0;i<100000;i++){
c=xmlDoc.getElementsByTagName("a");
}
document.write("getElementsByTagName: ",new Date()-d1);
d1=new Date();
try{
for(var i=0;i<100000;i++){
c=xmlDoc.selectNodes("a");
}
document.write("<br/>selectNodes: ",new Date()-d1);
}catch(ex){document.write("<br/>error:"+ex)}
在IE下selectNodes还是快多了，
可以FF下却没有这个方法，google了下，找了方法，使用XPathEvaluator来实现，下面是具体实现，不过效率就不太理想了：
复制代码 代码如下:
if (!window.ActiveXObject) {
(function(){
var oEvaluator=new XPathEvaluator(),oResult;
XMLDocument.prototype.selectNodes = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
var aNodes = [];
if (oResult != null) {
var oElement = oResult.iterateNext();
while (oElement) {
aNodes[aNodes.length]=oElement;
oElement = oResult.iterateNext();
}
}
return aNodes;
}
})()
}
evaluate(xpathExpression, contextNode, namespaceResolver, resultType, result);
Returns an XPathResult based on an XPath expression and other given parameters.
xpathExpression is a string representing the XPath to be evaluated.
contextNode specifies the context node for the query (see the [http://www.w3.org/TR/xpath XPath specification). It's common to pass document as the context node.
namespaceResolver is a function that will be passed any namespace prefixes and should return a string representing the namespace URI associated with that prefix. It will be used to resolve prefixes within the XPath itself, so that they can be matched with the document. null is common for HTML documents or when no namespace prefixes are used.
resultType is an integer that corresponds to the type of result XPathResult to return. Use named constant properties, such as XPathResult.ANY_TYPE, of the XPathResult constructor, which correspond to integers from 0 to 9.
result is an existing XPathResult to use for the results. null is the most common and will create a new XPathResult
完整的测试页面：
复制代码 代码如下:
<!doctype HTML>
<html>
<head>
<title>selectNodes&getElementsByTagName</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="author" content="sohighthesky"/>
<meta name="Keywords" content="selectNodes vs getElementsByTagName"/>
</head>
<body>
</body>
<script type="text/javascript">
/*
*author:sohighthesky -- http://www.cnblogs.com/sohighthesky
*content: selectNodes vs getElementsByTagName
*/
if (!window.ActiveXObject) {
(function(){
var oEvaluator=new XPathEvaluator(),oResult;
XMLDocument.prototype.selectNodes = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
var aNodes = [];
if (oResult != null) {
var oElement = oResult.iterateNext();
while (oElement) {
aNodes[aNodes.length]=oElement;
oElement = oResult.iterateNext();
}
}
return aNodes;
}
XMLDocument.prototype.selectSingleNode = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
// FIRST_ORDERED_NODE_TYPE returns the first match to the xpath.
return oResult==null?null:oResult.singleNodeValue;
}
})()
}
var stringToDom=function(text) {
var doc;
if(window.ActiveXObject) {
doc = new ActiveXObject("MSXML2.DOMDocument");
doc.loadXML(text).documentElement;
} else {
doc = (new DOMParser()).parseFromString(text,"text/xml");
}
return doc;
}
var xmlDoc=stringToDom("<body><a href='a'>a</a><a href='b'>b</a></body>"),
c,
d1=new Date();
for(var i=0;i<100000;i++){
c=xmlDoc.getElementsByTagName("a");
}
document.write("getElementsByTagName: ",new Date()-d1);
d1=new Date();
try{
for(var i=0;i<100000;i++){
c=xmlDoc.selectNodes("a");
}
document.write("<br/>selectNodes: ",new Date()-d1);
}catch(ex){document.write("<br/>error:"+ex)}
/*
var n=xmlDoc.selectSingleNode("body/a"),doc=xmlDoc.selectSingleNode("body");//alert(n.childNodes[0].nodeValue)
for(var i=0;i<10000;i++){
doc.appendChild(n.cloneNode(true))
}
d1=new Date();
c=xmlDoc.getElementsByTagName("a");
document.write("<br/>getElementsByTagName: ",new Date()-d1);
d1=new Date();
c=xmlDoc.selectNodes("a");
document.write("<br/>selectNodes: ",new Date()-d1);
*/
</script>
</html>
复制代码 代码如下:
var stringToDom=function(text) {
var doc;
if(window.ActiveXObject) {
doc = new ActiveXObject("MSXML2.DOMDocument");
doc.loadXML(text).documentElement;
} else {
doc = (new DOMParser()).parseFromString(text,"text/xml");
}
return doc;
}
var xmlDoc=stringToDom("<body><a href='a'>a</a><a href='b'>b</a></body>"),
c,
d1=new Date();
for(var i=0;i<100000;i++){
c=xmlDoc.getElementsByTagName("a");
}
document.write("getElementsByTagName: ",new Date()-d1);
d1=new Date();
try{
for(var i=0;i<100000;i++){
c=xmlDoc.selectNodes("a");
}
document.write("<br/>selectNodes: ",new Date()-d1);
}catch(ex){document.write("<br/>error:"+ex)}
在IE下selectNodes还是快多了，
可以FF下却没有这个方法，google了下，找了方法，使用XPathEvaluator来实现，下面是具体实现，不过效率就不太理想了：
复制代码 代码如下:
if (!window.ActiveXObject) {
(function(){
var oEvaluator=new XPathEvaluator(),oResult;
XMLDocument.prototype.selectNodes = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
var aNodes = [];
if (oResult != null) {
var oElement = oResult.iterateNext();
while (oElement) {
aNodes[aNodes.length]=oElement;
oElement = oResult.iterateNext();
}
}
return aNodes;
}
})()
}
evaluate(xpathExpression, contextNode, namespaceResolver, resultType, result);
Returns an XPathResult based on an XPath expression and other given parameters.
xpathExpression is a string representing the XPath to be evaluated.
contextNode specifies the context node for the query (see the [http://www.w3.org/TR/xpath XPath specification). It's common to pass document as the context node.
namespaceResolver is a function that will be passed any namespace prefixes and should return a string representing the namespace URI associated with that prefix. It will be used to resolve prefixes within the XPath itself, so that they can be matched with the document. null is common for HTML documents or when no namespace prefixes are used.
resultType is an integer that corresponds to the type of result XPathResult to return. Use named constant properties, such as XPathResult.ANY_TYPE, of the XPathResult constructor, which correspond to integers from 0 to 9.
result is an existing XPathResult to use for the results. null is the most common and will create a new XPathResult
完整的测试页面：
复制代码 代码如下:
<!doctype HTML>
<html>
<head>
<title>selectNodes&getElementsByTagName</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="author" content="sohighthesky"/>
<meta name="Keywords" content="selectNodes vs getElementsByTagName"/>
</head>
<body>
</body>
<script type="text/javascript">
/*
*author:sohighthesky -- http://www.cnblogs.com/sohighthesky
*content: selectNodes vs getElementsByTagName
*/
if (!window.ActiveXObject) {
(function(){
var oEvaluator=new XPathEvaluator(),oResult;
XMLDocument.prototype.selectNodes = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
var aNodes = [];
if (oResult != null) {
var oElement = oResult.iterateNext();
while (oElement) {
aNodes[aNodes.length]=oElement;
oElement = oResult.iterateNext();
}
}
return aNodes;
}
XMLDocument.prototype.selectSingleNode = function(sXPath) {
oResult = oEvaluator.evaluate(sXPath, this, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
// FIRST_ORDERED_NODE_TYPE returns the first match to the xpath.
return oResult==null?null:oResult.singleNodeValue;
}
})()
}
var stringToDom=function(text) {
var doc;
if(window.ActiveXObject) {
doc = new ActiveXObject("MSXML2.DOMDocument");
doc.loadXML(text).documentElement;
} else {
doc = (new DOMParser()).parseFromString(text,"text/xml");
}
return doc;
}
var xmlDoc=stringToDom("<body><a href='a'>a</a><a href='b'>b</a></body>"),
c,
d1=new Date();
for(var i=0;i<100000;i++){
c=xmlDoc.getElementsByTagName("a");
}
document.write("getElementsByTagName: ",new Date()-d1);
d1=new Date();
try{
for(var i=0;i<100000;i++){
c=xmlDoc.selectNodes("a");
}
document.write("<br/>selectNodes: ",new Date()-d1);
}catch(ex){document.write("<br/>error:"+ex)}
/*
var n=xmlDoc.selectSingleNode("body/a"),doc=xmlDoc.selectSingleNode("body");//alert(n.childNodes[0].nodeValue)
for(var i=0;i<10000;i++){
doc.appendChild(n.cloneNode(true))
}
d1=new Date();
c=xmlDoc.getElementsByTagName("a");
document.write("<br/>getElementsByTagName: ",new Date()-d1);
d1=new Date();
c=xmlDoc.selectNodes("a");
document.write("<br/>selectNodes: ",new Date()-d1);
*/
</script>
</html>
南强小屋 Design By 杰米
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免责声明：本站文章均来自网站采集或用户投稿，网站不提供任何软件下载或自行开发的软件！ 如有用户或公司发现本站内容信息存在侵权行为，请邮件告知！ 858582#qq.com
南强小屋 Design By 杰米
暂无getElementsByTagName vs selectNodes效率 及兼容的selectNodes实现的评论...
稳了！魔兽国服回归的3条重磅消息！官宣时间再确认！
昨天有一位朋友在大神群里分享，自己亚服账号被封号之后居然弹出了国服的封号信息对话框。
这里面让他访问的是一个国服的战网网址，com.cn和后面的zh都非常明白地表明这就是国服战网。
而他在复制这个网址并且进行登录之后，确实是网易的网址，也就是我们熟悉的停服之后国服发布的暴雪游戏产品运营到期开放退款的说明。这是一件比较奇怪的事情，因为以前都没有出现这样的情况，现在突然提示跳转到国服战网的网址，是不是说明了简体中文客户端已经开始进行更新了呢？