Can't get sort to work on multiarray

I have a multiarray that has a timestamp as one of the elements and I trying to sort on that. The example below has the dates in descending order but I want them in ascending order. So the out put is

    [first] => Array
        [item1] => d_2013-04-07
        [date] => 1365336914
 
        [item2] => d_2012-09-09
        [date] => 1347192912
 
    [second] => Array
        [item1] => d_2013-04-07
        [date] => 1365336914
 
        [item2] => d_2012-09-09
        [date] => 1347192912

Code (markup):

but I need it to be

    [first] => Array
        [item2] => d_2012-09-09
        [date] => 1347192912
       
        [item1] => d_2013-04-07
        [date] => 1365336914
 
    [second] => Array
        [item2] => d_2012-09-09
        [date] => 1347192912
 
        [item1] => d_2013-04-07
        [date] => 1365336914

Code (markup):

Here's the code.

<?php
 
$arry = array();
$arry['first'] = array( array('item1' => 'd_2013-04-07', 'date' => '1365336914'),
                array('item2' => 'd_2012-09-09', 'date' => '1347192912'));
$arry['second'] = array( array('item1' => 'd_2013-04-07', 'date' => '1365336914'),
                array('item2' => 'd_2012-09-09', 'date' => '1347192912'));
       
?> <pre> <?php
print_r($arry);
?> </pre><?php 
 
function cmp($a, $b) {
  return strcmp($a["date"], $b["date"]);
}
 
foreach($arry as $single) {
  uasort($single, "cmp");
}
 
?> <pre> <?php
print_r($arry);
?> </pre>

PHP:

I've tried a number of sorting functions but none seem to work. I think it may be to do with my loop where I sort. Maybe the array I sort is just a copy of the main array but, if that is it, I don't know how to set the results in the main array. Would someone take a look and point out my problem, please?

 

<?php
 
$arry = array();
$arry['first'] = array( array('item1' => 'd_2013-04-07', 'date' => '1365336914'),
                array('item2' => 'd_2012-09-09', 'date' => '1347192912'));
$arry['second'] = array( array('item1' => 'd_2013-04-07', 'date' => '1365336914'),
                array('item2' => 'd_2012-09-09', 'date' => '1347192912'));
       
// Date sorting function:
function sort_by_date($x, $y) {
  return ((int)$x['date'] > (int)$y['date']);     
}

 echo 'unSorted: ,<br>';
 echo '<pre>';
 print_r($arry);
 echo '</pre>';
 
foreach ($arry as $key => $value) {
    uasort($arry[$key], 'sort_by_date');    
}

 echo 'Sorted: <br>';
 echo '<pre>';
 print_r($arry);
 echo '</pre>';
 

PHP:

 

strider fixed the big two errors -- you weren't actually modifying $single -- his passing the $key lets it be targeted. The second error being attempting to use strcmp to compare to integers.

That first error, there's a simpler way, passing by reference... where you had:
foreach ($arry as $single)

just add a & before $single, and now you can make changes.

<?php
 
$arry = [
	'first' => [
		[
			'id' => 'd_2013-04-07',
			'date' => '1365336914'
		],[
			'id' => 'd_2012-09-09',
			'date' => '1347192912'
		]
	],
	'second' => [
		[
			'item1' => 'd_2013-04-07',
			'date' => '1365336914'
		],[
			'item2' => 'd_2012-09-09',
			'date' => '1347192912'
		]
	]
];

echo '<pre>',print_r($arry),'</pre>';
	
function compareDates($a, $b) {
	return $a['date'] > $b['date'];
}
 
foreach($arry as &$single) {
	uasort($single, 'compareDates');
}
 
echo '<pre>',print_r($arry),'</pre>';
?>

Code (markup):

That's PHP 5.4+ only code, they let us do JS style arrays now.

 

strider fixed the big two errors -- you weren't actually modifying $single -- his passing the $key lets it be targeted. The second error being attempting to use strcmp to compare to integers.

That first error, there's a simpler way, passing by reference... where you had:
foreach ($arry as $single)

just add a & before $single, and now you can make changes.

<?php
 
$arry = [
	'first' => [
		[
			'item1 => 'd_2013-04-07',
			'date' => '1365336914'
		],[
			'item2' => 'd_2012-09-09',
			'date' => '1347192912'
		]
	],
	'second' => [
		[
			'item1' => 'd_2013-04-07',
			'date' => '1365336914'
		],[
			'item2' => 'd_2012-09-09',
			'date' => '1347192912'
		]
	]
];

echo '<pre>',print_r($arry),'</pre>';
	
function compareDates($a, $b) {
	return $a['date'] > $b['date'];
}
 
foreach($arry as &$single) {
	uasort($single, 'compareDates');
}
 
echo '<pre>',print_r($arry),'</pre>';
?>

Code (markup):

That's PHP 5.4+ only code, they let us do JS style arrays now.

 

Thank you both for very much the replies. My code is working now.