dimensional Array by Value
How can I sort this array by the value of the "order" key? Even though the values are currently sequential, they will not always be.
Array
(
[0] => Array
(
[hashtag] => a7e87329b5eab8578f4f1098a152d6f4
[title] => Flower
[order] => 3
)
[1] => Array
(
[hashtag] => b24ce0cd392a5b0b8dedc66c25213594
[title] => Free
[order] => 2
)
[2] => Array
(
[hashtag] => e7d31fc0602fb2ede144d18cdffd816b
[title] => Ready
[order] => 1
)
)
Try a usort
: If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:
function sortByOrder($a, $b) {
return $a['order'] - $b['order'];
}
usort($myArray, 'sortByOrder');
Starting in PHP 5.3, you can use an anonymous function:
usort($myArray, function($a, $b) {
return $a['order'] - $b['order'];
});
And finally with PHP 7 you can use the "spaceship operator":
usort($myArray, function($a, $b) {
return $a['order'] <=> $b['order'];
});
To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.
usort($myArray, function($a, $b) {
$retval = $a['order'] <=> $b['order'];
if ($retval == 0) {
$retval = $a['suborder'] <=> $b['suborder'];
if ($retval == 0) {
$retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
}
}
return $retval;
});
If you need to retain key associations, use uasort()
- see comparison of array sorting functions in the manual
function aasort (&$array, $key) {
$sorter=array();
$ret=array();
reset($array);
foreach ($array as $ii => $va) {
$sorter[$ii]=$va[$key];
}
asort($sorter);
foreach ($sorter as $ii => $va) {
$ret[$ii]=$array[$ii];
}
$array=$ret;
}
aasort($your_array,"order");
我使用这个功能:
function array_sort_by_column(&$arr, $col, $dir = SORT_ASC) {
$sort_col = array();
foreach ($arr as $key=> $row) {
$sort_col[$key] = $row[$col];
}
array_multisort($sort_col, $dir, $arr);
}
array_sort_by_column($array, 'order');
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