How to parse json array and append it to the datatables - php

Question

I am unable to append the values to data tables, PHP file giving the JSON response but I am unable to append the data to the data table. I have used the following code for JSON response
GetKeyWordBids.php
array_push($ret, array("keyword"=>$keyword, "svol"=>$search_volume));
}
//print_r($ret);
echo json_encode($ret);
And Json Response:
[{
"keyword": "interventional cardiology",
"svol": 6600
},{
"keyword": "pediatric cardiology",
"svol": 5400
},{
"keyword": "cardiology jobs",
"svol": 1300
},{
"keyword": "cardiology associates",
"svol": 6600
},{
"keyword": "interventional cardiology jobs",
"svol": 880
},{
"keyword": "european society of cardiology",
"svol": 5400
},{
"keyword": "nuclear cardiology",
"svol": 1600
}],
And My Jquery Code is :
$('#specialty').change(function(){
$("#example1").dataTable().fnDestroy();
var oTable = $('#example1').dataTable({
"aaSorting": []
});
var spevalue = $("#specialty option:selected").text();
var dataString='specialty='+ spevalue;
$.ajax({
type: "POST",
url: "GetKeyWordBids.php",
data: dataString,
success: function(s){
oTable.fnClearTable();
for(var i = 0; i < s.length; i++) {
oTable.fnAddData([
s[i]['keyword'][0],
s[i]['svol'][0]
]);
}
});
});
But I am getting the error shown below. Please let me know the changes that are required.
DataTables warning (table id = 'example1'): Requested unknown parameter '0' from the data source for row 0

Answer 1

The JSON parser is very strict about JSON. And then your actual recall of the data is badly formatted. So:
As per splash58's comment, make sure your dataType is JSON. In your browser's developer tools (or Firebug), look at the XHR. The tool should provide a tab for viewing the response as formatted JSON. If it doesn't, or if you saw an error on the request, it might be requested with bad headers, or returned with the wrong type.
The trailing comma might be ignored by a JavaScript interpreter in general, but the JSON parser is strict and won't like it. A quick way of double-checking your JSON formatting is to fire it into JSONLint.com to see if it validates. The one you supply above does not until you remove the comma at the end.
I assume you want the full "keyword" and "svol". The extra [0] is digging into the string and returning the first character. You're going too deep into the data! What you want is s[i]['keyword'] (or s[i].keyword) and s[i]['svol'] (or s[i].svol) per this fiddle: http://jsfiddle.net/v07tvuq8/
I'm not really sure that the combination of fnClearTable and fnAddData are what you are looking for. The DataTables API allows you to specify what each column should do at initialization time, and thereafter you should just need to call draw() on it. There shouldn't be a need for iterating over your data set.