我刚刚创建了一个ArrayHelper类，它可以使数值索引变得非常容易。

class ArrayHelper
{
    /*
        Inserts a value at the given position or throws an exception if
        the position is out of range.
        This function will push the current values up in index. ex. if 
        you insert at index 1 then the previous value at index 1 will 
        be pushed to index 2 and so on.
        $pos: The position where the inserted value should be placed. 
        Starts at 0.
    */
    public static function insertValueAtPos(array &$array, $pos, $value) {
        $maxIndex = count($array)-1;

        if ($pos === 0) {
            array_unshift($array, $value);
        } elseif (($pos > 0) && ($pos <= $maxIndex)) {
            $firstHalf = array_slice($array, 0, $pos);
            $secondHalf = array_slice($array, $pos);
            $array = array_merge($firstHalf, array($value), $secondHalf);
        } else {
            throw new IndexOutOfBoundsException();
        }

    }
}

例子:

$array = array('a', 'b', 'c', 'd', 'e');
$insertValue = 'insert';
\ArrayHelper::insertValueAtPos($array, 3, $insertValue);

开始$数组:

Array ( 
    [0] => a 
    [1] => b 
    [2] => c 
    [3] => d 
    [4] => e 
)

结果:

Array ( 
    [0] => a 
    [1] => b 
    [2] => c 
    [3] => insert 
    [4] => d 
    [5] => e 
)

我需要一些可以在键之前，替换，之后插入的东西;如果没有找到目标键，则在数组的开头或结尾添加。默认是在键后插入。

新功能

/**
 * Insert element into an array at a specific key.
 *
 * @param array $input_array
 *   The original array.
 * @param array $insert
 *   The element that is getting inserted; array(key => value).
 * @param string $target_key
 *   The key name.
 * @param int $location
 *   1 is after, 0 is replace, -1 is before.
 *
 * @return array
 *   The new array with the element merged in.
 */
function insert_into_array_at_key(array $input_array, array $insert, $target_key, $location = 1) {
  $output = array();
  $new_value = reset($insert);
  $new_key = key($insert);
  foreach ($input_array as $key => $value) {
    if ($key === $target_key) {
      // Insert before.
      if ($location == -1) {
        $output[$new_key] = $new_value;
        $output[$key] = $value;
      }
      // Replace.
      if ($location == 0) {
        $output[$new_key] = $new_value;
      }
      // After.
      if ($location == 1) {
        $output[$key] = $value;
        $output[$new_key] = $new_value;
      }
    }
    else {
      // Pick next key if there is an number collision.
      if (is_numeric($key)) {
        while (isset($output[$key])) {
          $key++;
        }
      }
      $output[$key] = $value;
    }
  }
  // Add to array if not found.
  if (!isset($output[$new_key])) {
    // Before everything.
    if ($location == -1) {
      $output = $insert + $output;
    }
    // After everything.
    if ($location == 1) {
      $output[$new_key] = $new_value;
    }

  }
  return $output;
}

输入代码

$array_1 = array(
  '0' => 'zero',
  '1' => 'one',
  '2' => 'two',
  '3' => 'three',
);
$array_2 = array(
  'zero'  => '0',
  'one'   => '1',
  'two'   => '2',
  'three' => '3',
);

$array_1 = insert_into_array_at_key($array_1, array('sample_key' => 'sample_value'), 2, 1);
print_r($array_1);
$array_2 = insert_into_array_at_key($array_2, array('sample_key' => 'sample_value'), 'two', 1);
print_r($array_2);

输出

Array
(
    [0] => zero
    [1] => one
    [2] => two
    [sample_key] => sample_value
    [3] => three
)
Array
(
    [zero] => 0
    [one] => 1
    [two] => 2
    [sample_key] => sample_value
    [three] => 3
)

试试这个===

$key_pos=0;
$a1=array("a"=>"red", "b"=>"green", "c"=>"blue", "d"=>"yellow");
$arrkey=array_keys($a1);
array_walk($arrkey,function($val,$key) use(&$key_pos) {
  if($val=='b')
    {
        $key_pos=$key;
    }
  });
$a2=array("e"=>"purple");
$newArray = array_slice($a1, 0, $key_pos, true) + $a2 +
        array_slice($a1, $key_pos, NULL, true);
print_r($newArray);

输出

Array (
      [a] => red
      [e] => purple
      [b] => green
      [c] => blue
      [d] => yellow )

我最近写了一个函数来做一些类似于你正在尝试的事情，这与clasvdb的答案类似。

function magic_insert($index,$value,$input_array ) {
  if (isset($input_array[$index])) {
    $output_array = array($index=>$value);
    foreach($input_array as $k=>$v) {
      if ($k<$index) {
        $output_array[$k] = $v;
      } else {
        if (isset($output_array[$k]) ) {
          $output_array[$k+1] = $v;
        } else {
          $output_array[$k] = $v;
        }
      } 
    }

  } else {
    $output_array = $input_array;
    $output_array[$index] = $value;
  }
  ksort($output_array);
  return $output_array;
}

基本上，它在一个特定的点插入，但通过向下移动所有项来避免覆盖。

我已经创建了一个函数(PHP 8.1)，它允许您将项插入到关联数组或数值数组:

function insertItemsToPosition(array $array, string|int $insertAfterPosition, array $itemsToAdd): array
    {
        $insertAfterIndex = array_search($insertAfterPosition, array_keys($array), true);
        if ($insertAfterIndex === false) {
            throw new \UnexpectedValueException(sprintf('You try to insert items to an array after the key "%s", but this key is not existing in given array. Available keys are: %s', $insertAfterPosition, implode(', ', array_keys($array))));
        }

        $itemsBefore = array_slice($array, 0, $insertAfterIndex + 1);
        $itemsAfter = array_slice($array, $insertAfterIndex + 1);

        return $itemsBefore + $itemsToAdd + $itemsAfter;
    }

这是一个老问题，但我在2014年发表了一篇评论，经常回到这个问题。我想我应该留下一个完整的答案。这不是最短的解决方案，但很容易理解。

在关联数组中插入一个新值，在有编号的位置，保留键并保持顺序。

$columns = array(
    'id' => 'ID',
    'name' => 'Name',
    'email' => 'Email',
    'count' => 'Number of posts'
);

$columns = array_merge(
    array_slice( $columns, 0, 3, true ),     // The first 3 items from the old array
    array( 'subscribed' => 'Subscribed' ),   // New value to add after the 3rd item
    array_slice( $columns, 3, null, true )   // Other items after the 3rd
);

print_r( $columns );

/*
Array ( 
    [id] => ID 
    [name] => Name 
    [email] => Email 
    [subscribed] => Subscribed 
    [count] => Number of posts 
)
*/