How to pass JS array via POST AJAX to PHP? - php

Question

Here is my code:
var var_ids = new Array();
var i = 0;
jQuery("select").each(function() {
var_ids[i] = jQuery("option:selected",this).val();
i++;
}
var $data = {
action: "do_something",
var_ids: var_ids,
};
jQuery.post(doajax.ajaxurl, $data, function(response) {
alert(response);
});
And in my php:
$ids = mysql_real_escape_string(trim($_POST['var_ids']));
exit(print_r($ids));
And it just returns garbage...So my question is how to pass an array via AJAX to post php?
Thank you.

Answer 1

Most likely you get unexpected results because you apply string-related functions trim and mysql_real_escape_string to array $_POST['var_ids']
As long as it is just an array of integers - the only mysql sanitize you need is casting to int:
$ids = array_map('intval', $_POST['var_ids']);
print_r($ids);

Answer 2

$_POST['var_ids'] is an array in your example on the PHP side. You can only call trim and mysql_real_escape_string on strings not arrays. Try this in php:
$postData = isset($_POST['var_ids'])?$_POST['var_ids']):null;
if(is_array($postData)){
foreach($postData as $key=>$value){
$postData[$key] = mysql_real_escape_string(trim($value));
}
}
Viola, $postData is now a PHP array with trimmed and escaped values.

Answer 3

It's in the docs about 1/4 of a way down titled pass arrays of data to the server
var var_ids = new Array('10','12','13');
var $data = {
action: "do_something",
'var_ids[]': var_ids,
};
jQuery.post(doajax.ajaxurl, $data, function(response) {
alert(response);
});

Answer 4

Make it json_encoded array ... And then You can json_decode() the array properly.

Answer 5

You'll have better luck converting the array to a JSON object (Javascript Object Notation) and sending it that way.
Javascript JSON Instructions
JSON PHP Reference

Answer 6

You can either post each of the items with the key items[], then you could access the array as $_POST['items'] or you can serialize the array, send it and unserialize in PHP (JSON.stringify and PHP json_decode).