php associative array key order (not sort)

nizzle picture nizzle · Feb 4, 2011 · Viewed 26.9k times · Source

My array:

$data = array('two' => 2, 'one' => 1, 'three' => 3);

Now, with when I iterate the array, the first value that will come up will probably be

$data['two'] // = 2 @ index[0]

right?

What if I want to move the $data[1] to the position of $data[0] ?

To rephrase:

How do I make the array look like this (so that 'one' comes up at $data[0])

$data = array('one' => 1, 'two' => 2, 'three' => 3

Why do I need this?

I use code igniter, the table->generate built-in function takes an assoc array and creates a table but offers no method of arranging the columns. This is why I would like to move the columns in the source array.

Answer

Diego Pino picture Diego Pino · Dec 21, 2012

Two possible solutions (without using array_splice):

1) Create a new array with the new order of the keys.

$new_keys = array('one', 'two', 'three');
$new_data = array();
foreach ($new_keys as $key) {
    $new_data[$key] = $data[$key];
}
$data = $new_data;

2) Move the element one upfront, remove it from $data and copy the rest of the array.

function rearrangeData($data) {
    $result['one'] = $data['one'];
    unset($data['one']);
    return array_merge($result, $data);
}    
$data = rearrangeData($data);