研究了一整天的json数据与ajax的数据传输，现在进行一个小的自我总结，仅供参考

1.关于ajax的认识

$.ajax()，是jquery下包装好的一个函数：参考地址：http://www.w3school.com.cn/jquery/ajax_ajax.asp

使用其跟php段进行通信。

//方法一：使用jquery包装好的$.AJAX()函数来实现，接下来的php代码也是根据该放松来写的

<script type="text/javascript">
  //jquery直接进行ajax的包装调用
       $(function(){     
         
            $("#subbtn").click(                     
                    function(){
                             //单引号+value没有括号
                        var name=document.getElementById('name').value;                  
                        var email=document.getElementById('email').value;
                        var content=document.getElementById('content').value;                                                            
                        var params={
                                "one":[{"name":name,"email":email,"content":content},{"name":"test","email":"test","content":"test"}],
                                "two":[{"name":"test1","email":"test2","content":"test2"},{"name":"test3","email":"test3","content":"test3"}]
                                        };                             
                        var url="deal.php";
                        $.ajax({
                            type:"post",
                            url:url,
                            data:params,
                            dataType:"json",
                            error:function()
                            {alert("error !")},
                            success:function(json){                              
                                 var back="<ul>";
                                 for(var i=0;i<(json.length);i++)
                                 {
                                     for(var j=0;j<json[i].length;j++)
                                         back+="<li>"+json[i][j]+"</li>";
                                 }         
                                  back+="</ul>";
                                 $("#backdata").html(back);
                                 $("#backdata").css({color:"green"});
                            }
                        });
                    });
        });    
    </script>

//方法二：自己创建XMLHttpRequest对象实现ajax

<script type="text/javascript">

var xmlhttp;

//创建XMLHttpRequest对象
    function creatXMLHttpRequest()
    {

//非IE浏览器创建XmlHttpRequest对象
        if(window.XMLHttpRequest)
        {
          xmlhttp=new XMLHttpRequest();
        }
        //IE浏览器创建XmlHttpRequest对象
        if(window.ActiveXObject)
        {
            try{
                xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e){
                try{
                    xmlhttp=new ActiveXObject("msxml2.XMLHTTP");
                }
                catch(ex){}
            }
        }
    }

//设置相应服务器后的回调函数
        function callbackhandle()
        {
            if(xmlhttp.readyState==4)
                document.getElementById("").innerHTML="数据正在加载。。。";
            if(xmlhttp.status==200)
            {
                document.write(xmlhttp.responseText);
            }
        }

//向服务器发出请求

function useXMLHttpRequest(url)
        {
            creatXMLHttpRequest();
            if(!xmlhttp)
            {
                alert("创建xmlhttp对象异常！")；
                return false;
            }
            xmlhttp.open("POSY",url,true);
            xmlhttp.onreadystatechange=callbackhandle();
            xmlhttp.send();
        }

//客户端利用该函数进服务的请求调用
        function requestDigit()
        {
            var usname=document.getElementById().valueOf();
            var url="";
            useXMLHttpRequest(url);
        }

</script>

PHP段代码：利用jquery下包装的$.ajax()方法来回传json格式的数据

<?php

$name=$_POST['one'];
$email=$_POST['two'];
//$content=$_POST['content'];
$id=time();
//echo json_encode($_POST);
$conn=mysqli_connect('localhost', 'root','', 'guestbook');
mysqli_query($conn,"SET NAMES 'utf8'");
$s1=$name[0]["name"];
$s2=$name[0]["email"];
$s3=$name[0]["content"];
$sql="insert into liuyan values('$id','$s1','$s2','$s3')";
if(mysqli_query($conn, $sql))
{   
  $ar=array();
  $one=array();
  $tow=array();
  $one[0]=$s1;
  $one[1]=$s2;  
  $tow[0]=$email[1]["name"];//按照数组的访问方式，可以换成其他下标，仅作测试使用
  $tow[1]=$email[1]["email"];  
  $ar[0]=$one;
  $ar[1]=$tow;
  echo json_encode($ar);
}else
{
 echo 'DFDFDFDFDFD';//可以直接回传字符串，但是前面的现实的代码需要改一下，本人没有进行更改
 
}
 mysqli_close($conn);
?>

json的数据格式参考：http://baike.baidu.com/link?url=DexXfOk-Dt2rCSYz3oe8FhYXGAsHH5Jh_MUm3YopvoRT80-le_iXQoIMtdOj5jWU4FLRVPRLB6Xuca9xzezebq