要在本地测试AJAX，首先是环境的搭建，因为XHR对象的open方法中参数url是指文件在服务器上的文件。下面以WampServer为例。
1. 下载wamp的安装包，下载地址为：http://221.181.72.84/softdl.360tpcdn.com/WampServer/WampServer_2.5.exe
2.安装wamp。按照步骤安装即可。
3.安装完wamp后，双击桌面上wamp的快捷方式启动wamp。
如果wamp正常启动后，任务栏右下角有绿色的图标：
接下来以W3C的几个完整的测试代码为例。
测试实例1：
ajax.html代码为：
<html>
<head>
<script type="text/javascript">
function showHint(str)//当用户在输入框中键入字符时，会执行函数“showHint（）”，该函数由“onkeyup”事件触发；
{
var xmlhttp;
if (str.length==0)
{
document.getElementById("txtHint").innerHTML="";
return;
}//如果输入框为空（str.length==0），则该函数清空txtHint占位符的内容，并退出函数；
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.open("GET","http://localhost/my/php/gethint.php?q="+str,true);
xmlhttp.send();
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
}//如果输入框不为空，showHint（）函数执行以下任务：1.创建XHR对象 2.把请求发送到服务器上的文件 3.当服务器响应就绪时执行函数 4.注意我们向url添加了一个函数q（带有输入框的内容）；
</script>
</head>
<body>
<h3>请在下面的输入框中键入字母（A - Z）：</h3>
<form action="">
姓氏：<input type="text" id="txt1" onkeyup="showHint(this.value)" />
</form>
<p>建议：<span id="txtHint"></span></p>
</body>
</html>
gethint.php代码为：
<?php
// 用名字来填充数组
$a[]="Anna";
$a[]="Brittany";
$a[]="Cinderella";
$a[]="Diana";
$a[]="Eva";
$a[]="Fiona";
$a[]="Gunda";
$a[]="Hege";
$a[]="Inga";
$a[]="Johanna";
$a[]="Kitty";
$a[]="Linda";
$a[]="Nina";
$a[]="Ophelia";
$a[]="Petunia";
$a[]="Amanda";
$a[]="Raquel";
$a[]="Cindy";
$a[]="Doris";
$a[]="Eve";
$a[]="Evita";
$a[]="Sunniva";
$a[]="Tove";
$a[]="Unni";
$a[]="Violet";
$a[]="Liza";
$a[]="Elizabeth";
$a[]="Ellen";
$a[]="Wenche";
$a[]="Vicky";
//获得来自 URL 的 q 参数
$q=$_GET["q"];
//如果 q 大于 0，则查找数组中的所有提示
if (strlen($q) > 0)
{
$hint="";
for($i=0; $i<count($a); $i++)
{
if (strtolower($q)==strtolower(substr($a[$i],0,strlen($q))))
{
if ($hint=="")
{
$hint=$a[$i];
}
else
{
$hint=$hint." , ".$a[$i];
}
}
}
}
// 如果未找到提示，则把输出设置为 "no suggestion"
// 否则设置为正确的值
if ($hint == "")
{
$response="no suggestion";
}
else
{
$response=$hint;
}
//输出响应
echo $response;
?>
最后把HTML文件和php文件保存在wamp安装目录下www文件夹下相同的目录下（我的是php文件夹）:
然后通过本地服务器打开html文件（比如我的是http://localhost/my/php/ajax.html）:
测试实例2：
xml.html代码：
<html>
<head>
<script type="text/javascript">
function loadXMLDoc(url)
{
var xmlhttp;
var txt,x,xx,i;
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
txt="<table border='1'><tr><th>Title</th><th>Artist</th></tr>";
x=xmlhttp.responseXML.documentElement.getElementsByTagName("CD");
for (i=0;i<x.length;i++)
{
txt=txt + "<tr>";
xx=x[i].getElementsByTagName("TITLE");
{
try
{
txt=txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
}
catch (er)
{
txt=txt + "<td> </td>";
}
}
xx=x[i].getElementsByTagName("ARTIST");
{
try
{
txt=txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
}
catch (er)
{
txt=txt + "<td> </td>";
}
}
txt=txt + "</tr>";
}
txt=txt + "</table>";
document.getElementById('txtCDInfo').innerHTML=txt;
}
}
xmlhttp.open("GET",url,true);
xmlhttp.send();
}
</script>
</head>
<body>
<div id="txtCDInfo">
<button onclick="loadXMLDoc('http://localhost/my/php/cd_catalog.xml')">获得 CD 信息</button>
</div>
</body>
</html>
cd_catalog.xml代码为：
<CATALOG> <CD> <TITLE>Empire Burlesque</TITLE> <ARTIST>Bob Dylan</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>Columbia</COMPANY> <PRICE>10.90</PRICE> <YEAR>1985</YEAR> </CD> <CD> <TITLE>Hide your heart</TITLE> <ARTIST>Bonnie Tyler</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>CBS Records</COMPANY> <PRICE>9.90</PRICE> <YEAR>1988</YEAR> </CD> <CD> <TITLE>Greatest Hits</TITLE> <ARTIST>Dolly Parton</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>RCA</COMPANY> <PRICE>9.90</PRICE> <YEAR>1982</YEAR> </CD> <CD> <TITLE>Still got the blues</TITLE> <ARTIST>Gary Moore</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Virgin records</COMPANY> <PRICE>10.20</PRICE> <YEAR>1990</YEAR> </CD> <CD> <TITLE>Eros</TITLE> <ARTIST>Eros Ramazzotti</ARTIST> <COUNTRY>EU</COUNTRY> <COMPANY>BMG</COMPANY> <PRICE>9.90</PRICE> <YEAR>1997</YEAR> </CD> <CD> <TITLE>One night only</TITLE> <ARTIST>Bee Gees</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Polydor</COMPANY> <PRICE>10.90</PRICE> <YEAR>1998</YEAR> </CD> <CD> <TITLE>Sylvias Mother</TITLE> <ARTIST>Dr.Hook</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>CBS</COMPANY> <PRICE>8.10</PRICE> <YEAR>1973</YEAR> </CD> <CD> <TITLE>Maggie May</TITLE> <ARTIST>Rod Stewart</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Pickwick</COMPANY> <PRICE>8.50</PRICE> <YEAR>1990</YEAR> </CD> <CD> <TITLE>Romanza</TITLE> <ARTIST>Andrea Bocelli</ARTIST> <COUNTRY>EU</COUNTRY> <COMPANY>Polydor</COMPANY> <PRICE>10.80</PRICE> <YEAR>1996</YEAR> </CD> <CD> <TITLE>When a man loves a woman</TITLE> <ARTIST>Percy Sledge</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>Atlantic</COMPANY> <PRICE>8.70</PRICE> <YEAR>1987</YEAR> </CD> <CD> <TITLE>Black angel</TITLE> <ARTIST>Savage Rose</ARTIST> <COUNTRY>EU</COUNTRY> <COMPANY>Mega</COMPANY> <PRICE>10.90</PRICE> <YEAR>1995</YEAR> </CD> <CD> <TITLE>1999 Grammy Nominees</TITLE> <ARTIST>Many</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>Grammy</COMPANY> <PRICE>10.20</PRICE> <YEAR>1999</YEAR> </CD> <CD> <TITLE>For the good times</TITLE> <ARTIST>Kenny Rogers</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Mucik Master</COMPANY> <PRICE>8.70</PRICE> <YEAR>1995</YEAR> </CD> <CD> <TITLE>Big Willie style</TITLE> <ARTIST>Will Smith</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>Columbia</COMPANY> <PRICE>9.90</PRICE> <YEAR>1997</YEAR> </CD> <CD> <TITLE>Tupelo Honey</TITLE> <ARTIST>Van Morrison</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Polydor</COMPANY> <PRICE>8.20</PRICE> <YEAR>1971</YEAR> </CD> <CD> <TITLE>The very best of</TITLE> <ARTIST>Cat Stevens</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Island</COMPANY> <PRICE>8.90</PRICE> <YEAR>1990</YEAR> </CD> <CD> <TITLE>Stop</TITLE> <ARTIST>Sam Brown</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>A and M</COMPANY> <PRICE>8.90</PRICE> <YEAR>1988</YEAR> </CD> <CD> <TITLE>Bridge of Spies</TITLE> <ARTIST>T'Pau</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Siren</COMPANY> <PRICE>7.90</PRICE> <YEAR>1987</YEAR> </CD> <CD> <TITLE>Private Dancer</TITLE> <ARTIST>Tina Turner</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>Capitol</COMPANY> <PRICE>8.90</PRICE> <YEAR>1983</YEAR> </CD> <CD> <TITLE>Midt om natten</TITLE> <ARTIST>Kim Larsen</ARTIST> <COUNTRY>EU</COUNTRY> <COMPANY>Medley</COMPANY> <PRICE>7.80</PRICE> <YEAR>1983</YEAR> </CD> <CD> <TITLE>Pavarotti Gala Concert</TITLE> <ARTIST>Luciano Pavarotti</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>DECCA</COMPANY> <PRICE>9.90</PRICE> <YEAR>1991</YEAR> </CD> <CD> <TITLE>The dock of the bay</TITLE> <ARTIST>Otis Redding</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>Atlantic</COMPANY> <PRICE>7.90</PRICE> <YEAR>1987</YEAR> </CD> <CD> <TITLE>Picture book</TITLE> <ARTIST>Simply Red</ARTIST> <COUNTRY>EU</COUNTRY> <COMPANY>Elektra</COMPANY> <PRICE>7.20</PRICE> <YEAR>1985</YEAR> </CD> <CD> <TITLE>Red</TITLE> <ARTIST>The Communards</ARTIST> <COUNTRY>UK</COUNTRY> <COMPANY>London</COMPANY> <PRICE>7.80</PRICE> <YEAR>1987</YEAR> </CD> <CD> <TITLE>Unchain my heart</TITLE> <ARTIST>Joe Cocker</ARTIST> <COUNTRY>USA</COUNTRY> <COMPANY>EMI</COMPANY> <PRICE>8.20</PRICE> <YEAR>1987</YEAR> </CD> </CATALOG>
运行结果：
以上。