无法使用getJSON从php接收JSON

Question

I am trying to pass an array to the browser using php and jquery but I the when I try to use the 'data' returned from php's encode_json, it comes up undefined. I'm just learning php, jquery, and json and so far haven't found very good documentation on alot of this stuff, especially json, even in the books I have. Thanks in advance!

Here is a stripped down version of the jquery I have

$(document).ready(function(){
    var jsonResult;//I will want to be able to use the data in other functions

    $.getJSON("json.php", function(data){  
        jsonResult = data;
        var str;
        var nuts = [203,204,205,207];

        str = '<p>' + data[nuts[0]].NutraDesc + '</p>';
        $('#stuff').html(str);
        }
    );
});

This is the php:

    include_once 'databasePHP.php';
        $json_tst = $db->query( "SELECT  def.Nutr_No, NutrDesc, Nutr_Val, Units 
                FROM nutr_def as def  JOIN nut_data as data  ON def.Nutr_No = data.Nutr_No 
                WHERE data.NDB_No = 1001 LIMIT 0, 2");

        $food = array();

        while($row = $json_tst->fetch(PDO::FETCH_ASSOC))
        {
           $Nutr_No = $row['Nutr_No'];
           $food[$Nutr_No][] = array(
               'NutrDesc' => $row['NutrDesc'],
               'Nutr_Val' => $row['Nutr_Val'],
               'Units' => $row['Units']
           );
        };

        echo  json_encode($food);
?>

which returns this json which I checked on jsonlint.com and it said it was valid:

 {"203":[{"NutrDesc":"Protein","Nutr_Val":"0.85","Units":"g"}],"204":[{"NutrDesc":"Total lipid (fat)","Nutr_Val":"81.11","Units":"g"}]}

Answer 1

It probably doesn't work because the numbers should be strings. Try to add quotes around the numbers in nuts, like this:

var nuts = ["203","204","205","207"];

The following probably works as well:

str = '<p>' + data[String(nuts[0])].NutraDesc + '</p>';

Also, have you tried adding console.log(data); to the getJSON function to make sure it receives the JSON?

EDIT: Here is a working JSFiddle from your code: http://jsfiddle.net/rKLqM/

Things that were wrong:

• you weren't parsing the result as JSON ( JSON.parse )
• NutraDesc was spelled wrong
• You didn't convert the numbers to strings
• You needed to add [0] to the jsonResult because there's an extra array within it (see the [])

Answer 2

In Javascript object property can be accessed with obj["propName"]

So, change

var nuts = [203,204,205,207];

to

var nuts = ["203","204","205","207"];