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?
你是对的,你要找的函数是array_multisort()。
下面是一个直接摘自手册并根据你的情况进行调整的例子:
$price = array();
foreach ($inventory as $key => $row)
{
$price[$key] = $row['price'];
}
array_multisort($price, SORT_DESC, $inventory);
从PHP 5.5.0开始,你可以使用array_column()来代替foreach:
$price = array_column($inventory, 'price');
array_multisort($price, SORT_DESC, $inventory);
$inventory =
array(array("type"=>"fruit", "price"=>3.50),
array("type"=>"milk", "price"=>2.90),
array("type"=>"pork", "price"=>5.43),
);
function pricesort($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
$arr1 = array(
array('id'=>1,'name'=>'aA','cat'=>'cc'),
array('id'=>2,'name'=>'aa','cat'=>'dd'),
array('id'=>3,'name'=>'bb','cat'=>'cc'),
array('id'=>4,'name'=>'bb','cat'=>'dd')
);
$result1 = array_msort($arr1, array('name'=>SORT_DESC);
$result2 = array_msort($arr1, array('cat'=>SORT_ASC);
$result3 = array_msort($arr1, array('name'=>SORT_DESC, 'cat'=>SORT_ASC));
function array_msort($array, $cols)
{
$colarr = array();
foreach ($cols as $col => $order) {
$colarr[$col] = array();
foreach ($array as $k => $row) { $colarr[$col]['_'.$k] = strtolower($row[$col]); }
}
$eval = 'array_multisort(';
foreach ($cols as $col => $order) {
$eval .= '$colarr[\''.$col.'\'],'.$order.',';
}
$eval = substr($eval,0,-1).');';
eval($eval);
$ret = array();
foreach ($colarr as $col => $arr) {
foreach ($arr as $k => $v) {
$k = substr($k,1);
if (!isset($ret[$k])) $ret[$k] = $array[$k];
$ret[$k][$col] = $array[$k][$col];
}
}
return $ret;
}
如果需要对不同大小写的字符串数组进行排序,这将把排序数组的值更改为小写。
$data = [
[
'name' => 'jack',
'eyeColor' => 'green'
],
[
'name' => 'Amy',
'eyeColor' => 'brown'
],
[
'name' => 'Cody',
'eyeColor' => 'blue'
]
];
function toLowerCase($a) { return strtolower($a); }
$sortArray = array_map("toLowerCase",array_column($data, 'name'));
array_multisort($sortArray, SORT_ASC, $data);
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);