Uncaught Error: Not a valid 2D array

Question

I am creating a multidimensional array via an Ajax call to populate a Google Chart (Column). However the Array that is getting returned is causing this error:

Uncaught Error: Not a valid 2D array.  

This is the code that generates the array to send back:

$chartData = array();

    $i = 0;
    foreach ($hourVal as $value) {

        if($i <= 9){
           $chartData[] = array(
               "0" . $i => (int) $value
            );
        } else {
            $chartData[] = array(
                $i => (int) $value
            );
        }
        $i++;
    }

This is the array when I console.log:

[
 [
  "Terms",
  "Visits"
 ],
 {
  00: 88
 },
 {
  01: 30
 },
 {
  02: 44
 },
 {
  03: 20
 }
]

EDIT: I add a row at the beginning of the array and also json_encode:

array_unshift($chartData, array("Terms","Visits"));
echo json_encode($chartData);

Any ideas what is going on and how I can fix this?

Answer 1

That's not a 2D array. it's an array of objects (and one array). When you do json_encode , you only get an array if your PHP array is a numeric one (indexed starting at 0 ). Otherwise you get an object (since JavaScript/JSON doesn't have "associative arrays").

You need to make sure your array is numeric and indexed starting from 0 .

$chartData = array();

$i = 0;
foreach ($hourVal as $value) {
    $chartData[] = array(
        $i => (int) $value
    );
    $i++;
}

I don't know why you were doing "0" . $i "0" . $i , but that's what was causing your problem. That was creating an "associative array", which encodes as an object.

Answer 2

I have solved it, its because I was sending them through with a prefix of 0 and then it was making them the index of the array. Had to cut that bit out and send as string. Not desired but a fix :(