SyntaxError：JSON.parse：JSON数据的第1行第4列的意外字符

Question

json编码的字符串是

{
    "user": [{
        "id": "45",
        "name": "Raj",
        "loc": "kizhakood",
        "dist": "wayanad",
        "phone": "9815678421",
        "email": "rajsahanca@gmail.c",
        "gender": "male",
        "proofid": "2",
        "sslc": "SSLC",
        "plus2": "PLUS 2",
        "degree": "DEGREE",
        "pg": ""
    }]
}

当我尝试JSON.parse（responcetext）

时

  

SyntaxError：JSON.parse：JSON数据第1行第4列的意外字符

的javascript

<script type="application/javascript">
        function loadup(str){

        var xmlhttp;
        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)
        {
        var jsontext = xmlhttp.responseText;

        document.getElementById("mydiv").innerHTML=jsontext;

        var userobj=JSON.parse(jsontext);
        document.getElementById("myd").innerHTML=userobj.user[0].name;

    }
        } 

        xmlhttp.open("GET","plain.php?edit="+str,true);
        xmlhttp.send();
        }

    </script>`

php文件包含

<?php
   include"connection.php";
    $id = $_GET['edit'];
    $sql = "SELECT * FROM form WHERE id=$id";
    $result = $conn->query($sql);

    $row=$result->fetch_assoc();
     $json_res=array();
    $json_res = array('user'=>array($row));





    echo json_encode($json_res);


    $conn->close();
?>