在php中,我希望能够通过将元素移动到数组中的某些位置来重新排序关联数组。 不需要排序,只是我选择的重新排序。
例如,假设我有一个关联数组,如下所示:
array(
'a' => 'Element A',
'b' => 'Element B',
'c' => 'Element C',
);
在一种情况下,我可能想将 C 移到 B 之前并得到以下结果:
array(
'a' => 'Element A',
'c' => 'Element C',
'b' => 'Element B',
);
或者在另一种情况下,我可能想将 C 移到 A 之前并得到以下结果:
array(
'c' => 'Element C',
'a' => 'Element A',
'b' => 'Element B',
);
我想展示的,只是一种说"嘿,我想在另一个数组元素之前移动这个数组元素"或"嘿,我想移动这个数组元素以确保它出现在另一个数组元素之后"的方法
希望这是有道理的!
提前感谢任何愿意帮助我
$arr = array(
'a' => 1,
'b' => 2,
'move me' => 9,
'c' => 3,
'd' => 4,
);
嘿,我想在 ['b'] 之前移动 ['移动我']。我只需要 4 行代码就可以做到!
$i = 0; foreach($arr as &$val) $val = array('sort' => (++$i * 10), 'val' => $val);
$arr['move me']['sort'] = $arr['b']['sort'] - 5;
uasort($arr, function($a, $b) { return $a['sort'] > $b['sort']; });
foreach($arr as &$val) $val = $val['val'];
我做了一个易于使用的功能:
function move_item(&$ref_arr, $key1, $move, $key2 = null)
{
$arr = $ref_arr;
if($key2 == null) $key2 = $key1;
if(!isset($arr[$key1]) || !isset($arr[$key2])) return false;
$i = 0; foreach($arr as &$val) $val = array('sort' => (++$i * 10), 'val' => $val);
if(is_numeric($move))
{
if($move == 0 && $key1 == $key2) return true;
elseif($move == 0) { $tmp = $arr[$key1]['sort']; $arr[$key1]['sort'] = $arr[$key2]['sort']; $arr[$key2]['sort'] = $tmp; }
else $arr[$key1]['sort'] = $arr[$key2]['sort'] + ($move * 10 + ($key1 == $key2 ? ($move < 0 ? -5 : 5) : 0));
}
else
{
switch($move)
{
case 'up': $arr[$key1]['sort'] = $arr[$key2]['sort'] - ($key1 == $key2 ? 15 : 5); break;
case 'down': $arr[$key1]['sort'] = $arr[$key2]['sort'] + ($key1 == $key2 ? 15 : 5); break;
case 'top': $arr[$key1]['sort'] = 5; break;
case 'bottom': $arr[$key1]['sort'] = $i * 10 + 5; break;
default: return false;
}
}
uasort($arr, function($a, $b) { return $a['sort'] > $b['sort']; });
foreach($arr as &$val) $val = $val['val'];
$ref_arr = $arr;
return true;
}
例子:
move_item($arr, 'move me', 'up'); //move it one up
move_item($arr, 'move me', 'down'); //move it one down
move_item($arr, 'move me', 'top'); //move it to top
move_item($arr, 'move me', 'bottom'); //move it to bottom
move_item($arr, 'move me', -1); //move it one up
move_item($arr, 'move me', 1); //move it one down
move_item($arr, 'move me', 2); //move it two down
move_item($arr, 'move me', 'up', 'b'); //move it before ['b']
move_item($arr, 'move me', -1, 'b'); //move it before ['b']
move_item($arr, 'move me', 'down', 'b'); //move it after ['b']
move_item($arr, 'move me', 1, 'b'); //move it after ['b']
move_item($arr, 'move me', 2, 'b'); //move it two positions after ['b']
//Special syntax, to swap two elements:
move_item($arr, 'a', 0, 'd'); //Swap ['a'] with ['d']
我希望这对很多人有所帮助,因为它是一个很棒的功能!:D
例如,对于自定义排序,您可以创建一个按所需键顺序排列的数组,然后将值与它们相关联。例:
$input = array("a"=>"Element A","b"=>"Element B","c"=>"Element C");
$order = array("c","a","b");
$out = array();
foreach($order as $k) {
$out[$k] = $input[$k];
}
$out
中的元素将按指定的顺序排列。
如果你想交换两个值,你可以做一个这样的函数:
function array_swap($key1, $key2, $array) {
$newArray = array ();
foreach ($array as $key => $value) {
if ($key == $key1) {
$newArray[$key2] = $array[$key2];
} elseif ($key == $key2) {
$newArray[$key1] = $array[$key1];
} else {
$newArray[$key] = $value;
}
}
return $newArray;
}
困难的方法:)实际上,您可以利用array_slice()
的保留密钥功能。
$new_element = array('new_key' => 'value');
// if needed, find the insertion index by key
$index = array_search('key to search', array_keys($old_array));
// add element at index (note the last array_slice argument)
$new_array = array_slice($old_array, 0, $index+1, true) + $new_element + array_slice($old_array, $index+1, null, true);
我最喜欢 luky 的答案,但它需要指定所有键。大多数情况下,您只想在数组的开头对键的子集进行排序。此功能将帮助:
function reorder_assoc_array(
$cur, // current assoc array
$order // array conaining ordered (subset of) keys in $cur
) {
$result = [];
// first copy ordered key/values to result array
foreach($order as $key) {
$result[$key] = $cur[$key];
// unset key in original array
unset($cur[$key]);
}
// ... then copy all remaining keys that were not given in $order
foreach($cur as $key => $value) {
$result[$key] = $value;
}
return $result;
}
例:
$assoc_arr = [
'b' => 'bbb',
'a' => 'aaa',
'c' => 'ccc',
'd' => 'ddd'
];
// suppose we want to swap the first two keys and leave the remaining keys as is
$assoc_arr = reorder_assoc_array($assoc_arr, ['a', 'b']);
// ... the order of keys is now a, b, c, d
array_splice
不适用于关联数组,所以这里有一些更混乱的东西:
$keys = array_keys($arr);
$values = array_values($arr);
$keyIndex = array_search($someKey, $keys);
array_splice($keys, $keyIndex, 1);
array_splice($values, $keyIndex, 1);
$insertIndex = 1;
array_splice($keys, $insertIndex, 0, array($someKey));
array_splice($values, $insertIndex, 0, array($arr[$someKey]));
$arr = array_combine($keys, $values);
我在这里基于一个答案做了一个函数。 它需要对 ASSoC 数组进行排序,以及应该在其中重新排序的键数组
// $data = array of assoc array
// $newKeysOrder = array("c","a","b");
function resort_assoc_array_by_keys($data, $newKeysOrder) {
foreach($data as $v) {
$out = [];
foreach($newKeysOrder as $k) {
$out[$k] = $v[$k];
}
$new[] = $out;
}
return $new;
}