PHP:重新排序关联数组

时间:2012-07-01 14:03:36

标签: php

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。没有必要,只是重新排序我的选择。

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,我可能想在B之前移动C并得到以下结果:

array(
 'a' => 'Element A',
 'c' => 'Element C',
 'b' => 'Element B',
);

或在另一种情况下,我可能想要在A之前移动C并得到以下结果:

array(
 'c' => 'Element C',
 'a' => 'Element A',
 'b' => 'Element B',
);

我想要展示的,只是一种方法来说“嘿,我想在这个其他数组元素之前移动这个数组元素”或“嘿,我喜欢移动这个数组元素以确保它来之后这个其他数组元素'

希望这是有道理的!

感谢任何提前帮助我的人

7 个答案:

答案 0 :(得分:9)

对于自定义排序,您可以创建一个数组,该数组是所需的键顺序,然后将值与它们相关联。例如:

$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。

答案 1 :(得分:8)

$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']。我只用4行代码就可以做到这一点!

$i = 0; foreach($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']


我希望这能帮助很多人,因为它是一个很棒的功能! :d

答案 2 :(得分:2)

如果你想交换两个值,你可以创建一个这样的函数:

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;
    }

答案 3 :(得分:1)

这里有很多困难的方法:)事实上,你可以利用array_slice()的保留键功能。

$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);

答案 4 :(得分:0)

遗憾的是,

array_splice不适用于关联数组,所以这里有点麻烦:

$keys = array_keys($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);

答案 5 :(得分:0)

我在这里根据一个答案做了一个函数。它需要对assoc数组的数组进行排序,再加上应该使用它的键数组

// $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;
}

答案 6 :(得分:0)

我最喜欢luky的答案,但这需要指定所有键。大多数时候,您只想在数组的开头订购键的子集。此功能将帮助您:

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;
}

示例:

$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