Sort array of objects
I've had trouble with the examples in the PHP manual, so I'd like to ask this here...
I have an array of objects.. Is there a way to sort it based on the contents of the object?
For example, my array is:
Array
(
[0] => stdClass Object
(
[id] => 123
[alias] => mike
)
[1] => stdClass Object
(
[id] => 456
[alias] => alice
)
[2] => stdClass Object
(
[id] => 789
[alias] => zeke
)
[3] => stdClass Object
(
[id] => 987
[alias] => dave
)
)
How do I sort the array by the [alias] of the objects?
In the example, the output should be:
Array
(
[0] => stdClass Object
开发者_C百科(
[id] => 456
[alias] => alice
)
[1] => stdClass Object
(
[id] => 987
[alias] => dave
)
[2] => stdClass Object
(
[id] => 123
[alias] => mike
)
[3] => stdClass Object
(
[id] => 789
[alias] => zeke
)
)
Thanks in advance!
Use usort()
. You specify a function to do that comparison and the sort is done based on the function. E.g.:
function my_comparison($a, $b) {
return strcmp($a->alias, $b->alias);
}
$arr = ...;
usort($arr, 'my_comparison');
I think the order is missing, I've found this other function
<?php
/**
* Sort array of objects by field.
*
* @autor Lea Hayes
* @param array $objects Array of objects to sort.
* @param string $on Name of field.
* @param string $order (ASC|DESC)
*/
function sort_on_field(&$objects, $on, $order = 'ASC') {
$comparer = ($order === 'DESC')
? "return -strcmp(\$a->{$on},\$b->{$on});"
: "return strcmp(\$a->{$on},\$b->{$on});";
usort($objects, create_function('$a,$b', $comparer));
}
$order = ($_GET['order'] === 'asc') ? 'ASC' : 'DESC';
sort_on_field($arr, 'alias', $order);
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