Chrome re-ordering object keys if numerics, is that normal/expected

Question

I noticed that certain code that evaluates some shoe sizes for an e-commerce site and outputs them on screen is messing up the order in Chrome.

JSON given can be:

Answer 1

My keys were too important for me to convert them to strings. Instead I created another array which just maintained the order of the keys.

<?php 
$origArray = valueReturnedFromFunction();
$preservedOrder = array_keys($origArray);
?>
<script>
var origArray = <?php echo json_encode($origArray)?>;
var preservedOrder = <?php echo json_encode($preservedOrder )?>;

for(i in preservedOrder){
    var item = origArray[i];
    ...
}
</script>