给定这个数组:
$inventory = array(
array("type"=>"fruit", "price"=>3.50),
array("type"=>"milk", "price"=>2.90),
array("type"=>"pork", "price"=>5.43),
);
我想按价格排序$inventory的元素,以获得:
$inventory = array(
array("type"=>"pork", "price"=>5.43),
array("type"=>"fruit", "price"=>3.50),
array("type"=>"milk", "price"=>2.90),
);
我该怎么做呢?
从PHP 7.4开始,你可以使用arrow函数:
usort(
$inventory,
fn(array $a, array $b): int => $b['price'] <=> $a['price']
);
代码(演示):
$inventory = [
['type' => 'fruit', 'price' => 3.50],
['type' => 'milk', 'price' => 2.90],
['type' => 'pork', 'price' => 5.43],
];
usort(
$inventory,
fn(array $a, array $b): int => $b['price'] <=> $a['price']
);
print_r($inventory);
(浓缩)输出:
Array
(
[0] => Array ([type] => pork, [price] => 5.43)
[1] => Array ([type] => fruit, [price] => 3.5)
[2] => Array ([type] => milk, [price] => 2.9)
)
这是我很久以前发现的一个方法,并进行了一些清理。这工作得很好,并且可以快速更改为接受对象。
/**
* A method for sorting arrays by a certain key:value.
* SortByKey is the key you wish to sort by
* Direction can be ASC or DESC.
*
* @param $array
* @param $sortByKey
* @param $sortDirection
* @return array
*/
private function sortArray($array, $sortByKey, $sortDirection) {
$sortArray = array();
$tempArray = array();
foreach ( $array as $key => $value ) {
$tempArray[] = strtolower( $value[ $sortByKey ] );
}
if($sortDirection=='ASC'){ asort($tempArray ); }
else{ arsort($tempArray ); }
foreach ( $tempArray as $key => $temp ){
$sortArray[] = $array[ $key ];
}
return $sortArray;
}
要更改排序对象的方法,只需更改以下行:
$tempArray[] = strtolower($value[$sortByKey]);
来
$tempArray[] = strtolower($value->$sortByKey);
要运行该方法,只需执行
盘存、’price’’ASC’sortArray(美元);
$inventory =
array(array("type"=>"fruit", "price"=>3.50),
array("type"=>"milk", "price"=>2.90),
array("type"=>"pork", "price"=>5.43),
);
function pricesort($a, $b) {
$a = $a['price'];
$b = $b['price'];
if ($a == $b)
return 0;
return ($a > $b) ? -1 : 1;
}
usort($inventory, "pricesort");
// uksort($inventory, "pricesort");
print("first: ".$inventory[0]['type']."\n\n");
// for usort(): prints milk (item with lowest price)
// for uksort(): prints fruit (item with key 0 in the original $inventory)
// foreach prints the same for usort and uksort.
foreach($inventory as $i){
print($i['type'].": ".$i['price']."\n");
}
输出:
first: pork
pork: 5.43
fruit: 3.5
milk: 2.9
这个函数在所有主要的PHP版本上都可以100%运行,并且在PHP5, PHP7, PHP8上都进行了测试。
function sort_my_array($array, $order_by, $order)
{
switch ($order) {
case "asc":
usort($array, function ($first, $second) use ($order_by) {
if (version_compare(PHP_VERSION, '7.0.0') >= 0) {
return $first[$order_by] <=> $second[$order_by];
} else {
$array_cmp = strcmp($first[$order_by], $second[$order_by]);
return $array_cmp ;
}
});
break;
case "desc":
usort($certificates, function ($first, $second) use ($order_by) {
if (version_compare(PHP_VERSION, '7.0.0') >= 0) {
return $first[$order_by] <=> $second[$order_by];
} else {
$array_cmp = strcmp($first[$order_by], $second[$order_by]);
return -$array_cmp ;
}
});
break;
default:
break;
}
return $array;
}
虽然其他人正确地建议使用array_multisort(),但由于某种原因,似乎没有答案承认array_column()的存在,它可以极大地简化解决方案。所以我的建议是:
array_multisort(array_column($inventory, 'price'), SORT_DESC, $inventory);
如果你想对字符串进行不区分大小写排序,你可以使用SORT_NATURAL|SORT_FLAG_CASE
array_multisort(array_column($inventory, 'key_name'), SORT_DESC, SORT_NATURAL|SORT_FLAG_CASE, $inventory);