JSON Array Not Decoding With Eval

I have two files, one containing an array in PHP that is echoed via json_encode, and the other full of javascript functions for a webpage. One such function, that looks like this (and is unfinished):

/*
 * Function: selectVictim
 * Called from function laserOn()
 *
 * Selects a random victim from a list of victims
 *
 * @return String: victim
 */
function selectVictim()
{
var params = "url=queenofsheep.com/Sheep/victims.php";
var request = new ajaxRequest();

request.open("POST", "victims.php", true);
request.setRequestHeader("Content-Type",
                             "application/x-www-form-urlencoded");
request.setRequestHeader("Content-Length", params.length);
request.setRequestHeader("Connection", "close");

request.onreadystatechange = function ()
{
    if (this.readyState == 4)
    {
        if (this.status == 200)
        {
            if (this.responseText != null )
            {
                var vicString = this.responseText;
                var vicArray = eval('"'+vicString+'"');
                //var vicArray = vicString.split(',');
                //var numVic = Math.flo开发者_运维百科or(Math.random() * (vicArray - 1));
                alert(vicArray);
            }
            else alert("Ajax error: No data received");
        }
        else alert("Ajax Error: " + this.statusText);
    }
}

request.send(params);
}

Is supposed to take in the array from the other file and do things to it that are beyond the scope of this question. Unfortunately, while this.responseText contains a JSON encoded array of the format

var jsonArr = 
     ["1","2,","3"]

activating the function does nothing, and evaling this.responseText yields "undefined."

What am I doing wrong here? I can provide more examples of the real code, the actual array, whatever, if need be. This is driving me crazy.

Try adding "(" and ")" to the Eval Function. That's how I've seen it done in the past

var myObject = eval('(' + vicString + ')');

Use request instead of this. this refers to the window object.

Edit: if var jsonArr=[1, 2, 3]; is literally the response, you should use eval(vicString+';jsonArr'); if you can't alter the response text.

If you'd run 'eval("var test=[1,2,3];")', you'ld have seen that it indeed returns undefined. But this isn't a good practice in using JSON.

Set the content type of the response in the server to "application/json" and you won't have to use eval anymore.
Also you would be better of using an ajax framework instead of using your own ajax functions.