假设我有这个数组:
$array = array(
array("id" => 7867867, "animal" => "Dog"),
array("id" => 3452342, "animal" => "Lion"),
array("id" => 1231233, "animal" => "Lion"),
array("id" => 5867867, "animal" => "Dog"),
array("id" => 1111111, "animal" => "Zeebra"),
array("id" => 2222222, "animal" => "Cat"),
array("id" => 3333333, "animal" => "Cat"),
array("id" => 4444444, "animal" => "Zeebra")
);
现在我一直在尝试使用php排序函数来根据特定规则对其进行排序(不是按字母顺序排列)
客户希望此信息按“Lion first,Dog second,Zeebra third,Cat 4th”排序。
这样的事情:
$array = array(
array("id" => 3452342, "animal" => "Lion"),
array("id" => 1231233, "animal" => "Lion"),
array("id" => 7867867, "animal" => "Dog"),
array("id" => 5867867, "animal" => "Dog"),
array("id" => 4444444, "animal" => "Zeebra"),
array("id" => 1111111, "animal" => "Zeebra"),
array("id" => 2222222, "animal" => "Cat"),
array("id" => 3333333, "animal" => "Cat"),
);
数组将使用“动物”值进行排序,并且将基于预先确定的规则。
我试图找出php排序函数,但我只能按照字母顺序或数字顺序对数组进行排序。
我已经开始工作的是一个if语句和循环块,我想尽快摆脱那些慢速代码。
答案 0 :(得分:6)
使用有关使用usort的Jonathan建议,您可以在单独的函数中定义自定义规则以进行排序,例如:
function getAnimalValue($animal) {
switch($animal) {
case 'Lion':
return 1;
case 'Dog':
return 2;
case 'Zeebra':
return 3;
case 'Cat':
return 4;
}
return 0;
}
然后,实现自己的比较功能:
function compare($itemA, $itemB) {
$a = getAnimalValue($itemA['animal']);
$b = getAnimalValue($itemB['animal']);
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
最后,使用compare函数调用usort:
usort($array, "compare");
答案 1 :(得分:1)
检查我们。继承人参考:
http://www.php.net/manual/en/function.usort.php
示例:
function cmp($a, $b) {
$order=array("Lion","Dog","Zebra","Cat");
if ($a["animal"] == $b["animal"]) {
return 0;
}
return (array_search($a["animal"],$order) < array_search($b["animal"],$order)) ? -1 : 1;
}
$array = array(
array("id" => 7867867, "animal" => "Dog"),
array("id" => 3452342, "animal" => "Lion"),
array("id" => 1231233, "animal" => "Lion"),
array("id" => 5867867, "animal" => "Dog"),
array("id" => 1111111, "animal" => "Zebra"),
array("id" => 2222222, "animal" => "Cat"),
array("id" => 3333333, "animal" => "Cat"),
array("id" => 4444444, "animal" => "Zebra")
);
$mySortedArray=usort($array, "cmp");
答案 2 :(得分:0)
这有点丑陋,但确实有效。
// Set our rules, the key is the order
$rules = array(0=>"Dog",1=>"Lion",2=>"Zeebra",3=>"Cat");
// Our array
$array = array(
array("id" => 7867867, "animal" => "Dog"),
array("id" => 3452342, "animal" => "Lion"),
array("id" => 1231233, "animal" => "Lion"),
array("id" => 5867867, "animal" => "Dog"),
array("id" => 1111111, "animal" => "Zeebra"),
array("id" => 2222222, "animal" => "Cat"),
array("id" => 3333333, "animal" => "Cat"),
array("id" => 4444444, "animal" => "Zeebra")
);
// Split each animal into a arrays per animal
foreach( $array as $item ){
$animals[ $item['animal'] ][] = $item;
}
// Loop our rules (dogs, then lions, etc) and put our mini arrays in a final sorted_array.
foreach( $rules as $animal_order => $animal_name ){
foreach( $animals[$animal_name] as $animal ){
$sorted_animals[] = $animal;
}
}
print_r($sorted_animals);
答案 3 :(得分:0)
尝试:
function sortByAnimals($array, $animalOrderArray){
foreach($animalOrderArray as $v){
$aa[$v] = array();
}
foreach($array as $a){
foreach($aa as $i => $v){
if(preg_match("/^{$a['animal']}$/i", $i)){
array_push($aa[$i], $a);
break;
}
}
}
foreach($aa as $a){
foreach($a as $v){
$r[] = $v;
}
}
return $r;
}
$resArray = sortByAnimals($array, array('lion', 'dog', 'zeebra', 'cat'));
答案 4 :(得分:-2)
PHP7提供了“ spaceship operator”,使排序变得非常简单。
以下所有代码段都将利用查找数组来确定自定义排序顺序。
while(true)
代码:(Demo)
$priorities = array_flip(['Lion', 'Dog', 'Zeebra', 'Cat']);
PHP7.4 +代码:(Demo)
usort($array, function($a, $b) use ($priorities) {
return $priorities[$a['animal']] <=> $priorities[$b['animal']];
});
您的问题和样本数据表明,您在查找数组中总会承认所有动物。如果并非总是如此,那么您将需要在自定义函数中进行usort($array, fn($a, $b) => $priorities[$a['animal']] <=> $priorities[$b['animal']]);
调用,并确定是否要将丢失的动物放在列表的前面或后面。
以上两个代码段都提供相同的输出:
isset()