Reverse array in php - php

Question

array(7) {
[0]=> array(2) { ["id"]=> string(1) "9" ["roi"]=> float(0) }
[1]=> array(2) { ["id"]=> string(1) "1" ["roi"]=> float(0) }
[2]=> array(2) { ["id"]=> string(2) "10" ["roi"]=> float(0) }
[3]=> array(2) { ["id"]=> string(2) "14" ["roi"]=> float(0) }
[4]=> array(2) { ["id"]=> string(1) "4" ["roi"]=> float(0) }
[5]=> array(2) { ["id"]=> string(1) "5" ["roi"]=> float(141) }
[6]=> array(2) { ["id"]=> string(1) "6" ["roi"]=> float(2600) }
}
I would just like to reverse this, so id 6 (with roi of 2600) comes first in the array etc.
How can I do this? array_reverse() and rsort() does not work in this case

Answer 1

http://php.net/manual/en/function.array-reverse.php:
$newArray = array_reverse($theArray, true);
The important part is the true parameter, which preserves the keys.
Not convinced? You can see it in action on this codepad exampole.

Answer 2

foreach($array as $arr){
array_unshift($array, $arr);
array_pop($array);
}

Answer 3

$res = array(
0=>array("id"=>9, "roi"=>0),
1=>array("id"=>1,"roi"=>0),
2=>array("id"=>10,"roi"=>0),
3=>array("id"=>14,"roi"=>0),
4=>array("id"=>4,"roi"=>0),
5=>array("id"=>5,"roi"=>141),
6=>array("id"=>6,"roi"=>2600));
$res4 = array();
$count = count($res);
for($i=$count-1;$i>=0;$i--){
$res4[$i] =$res[$i];
}
print_r($res4);

Answer 4

You can use an usort() function, like so
$arr = array('......'); // your array
usort($arr, "my_reverse_array");
function my_reverse_array($a, $b) {
if($a['roi'] == $b['roi'])
{
return 0;
}
return ($a['roi'] < $b['roi']) ? -1 : 1;
}
This will make sure the item with the highest roi is first in the array.

Answer 5

$res = array(
0=>array("id"=>9, "roi"=>0),
1=>array("id"=>1,"roi"=>0),
2=>array("id"=>10,"roi"=>0),
3=>array("id"=>14,"roi"=>0),
4=>array("id"=>4,"roi"=>0),
5=>array("id"=>5,"roi"=>141),
6=>array("id"=>6,"roi"=>2600));
$count = count($res);
for ($i=0, $j=$count-1; $i<=floor($count/2); $i++, $j--) {
$temp = $res[$j];
$res[$j] = $res[$i];
$res[$i] = $temp;
}
echo '<pre>';
print_r($res);
echo '</pre>';

Answer 6

It's easy. May be use usort function of php like:
usort($arr, function($a, $b) {
return $b['roi'] - $a['roi'];
});
Just swap position $a and $b that is correct.