AJAX for PHP development_PHP tutorial

AJAX for PHP development

I just came across AJAX two days ago. I heard others say it is quite useful, and I feel it is necessary to learn it.
Let’s take an example of passing parameters to the php page through the get method:
test.html

<code class="hljs" xml="">
</code>

<input onclick="testcheck()" type="button" value="submit" />

test.js

<code class="hljs" javascript="">var xmlHttp;
function GetXmlHttpObject(){
    if (window.XMLHttpRequest){
      // code for IE7+, Firefox, Chrome, Opera, Safari
      xmlhttp=new XMLHttpRequest();
    }else{// code for IE6, IE5
      xmlhttp=new ActiveXObject(Microsoft.XMLHTTP);
    }
    return xmlhttp;
}
// -----------ajax方法-----------//
function testcheck(){
    xmlHttp=GetXmlHttpObject();
    if (xmlHttp==null){
        alert(&#39;您的浏览器不支持AJAX！&#39;);
        return;
    }

    var url=http://localhost/PHPTEST/index.php?isbn=110120;//这个地方一定要注意哦，刚开始的时候我在&lsquo;＝&rsquo;前面多了一个空格，结果造成了php页面获取不到参数，大家都一定要注意些哦
    xmlHttp.open(GET,url,true);
    xmlHttp.onreadystatechange=getOkGet;//发送事件后，收到信息了调用函数
    xmlHttp.send();
}
function getOkGet(){
    if(xmlHttp.readyState==1||xmlHttp.readyState==2||xmlHttp.readyState==3){
        // 本地提示：加载中

    }
    if (xmlHttp.readyState==4 && xmlHttp.status==200){
       alert(xmlHttp.responseText);
       alert(&#39;123&#39;);
        // 处理返回结果
    }
}
</code>

index.php

<code class="hljs" xml=""><!--?php 

header('Content-type:text/html');

if(isset($_GET['isbn'])){
    $isbn =$_GET['isbn'];

    if(!$isbn){
        echo(abc);

    //  print That request was not understood;

    }else if ($isbn ==110120) {
        echo($isbn);
    //  print JavaScript step by step;
    }
}else{
    echo(aaa);
}

?-->
</code>

In addition, the url of test.js should be the path where your file is located, don’t make a mistake, hehe
Let me show you the running effect below

http://www.bkjia.com/PHPjc/992671.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/992671.htmlTechArticleAJAX-AJAX for PHP development I just came across this stuff two days ago and heard others say it is quite useful. I feel the need to learn it. The following is an example of passing parameters to the php page through the get method...