可以在整数和字符串位置进行插入的函数:

/**
 * @param array      $array
 * @param int|string $position
 * @param mixed      $insert
 */
function array_insert(&$array, $position, $insert)
{
    if (is_int($position)) {
        array_splice($array, $position, 0, $insert);
    } else {
        $pos   = array_search($position, array_keys($array));
        $array = array_merge(
            array_slice($array, 0, $pos),
            $insert,
            array_slice($array, $pos)
        );
    }
}

整数的用法:

$arr = ["one", "two", "three"];
array_insert(
    $arr,
    1,
    "one-half"
);
// ->
array (
  0 => 'one',
  1 => 'one-half',
  2 => 'two',
  3 => 'three',
)

字符串的用法:

$arr = [
    "name"  => [
        "type"      => "string",
        "maxlength" => "30",
    ],
    "email" => [
        "type"      => "email",
        "maxlength" => "150",
    ],
];

array_insert(
    $arr,
    "email",
    [
        "phone" => [
            "type"   => "string",
            "format" => "phone",
        ],
    ]
);
// ->
array (
  'name' =>
  array (
    'type' => 'string',
    'maxlength' => '30',
  ),
  'phone' =>
  array (
    'type' => 'string',
    'format' => 'phone',
  ),
  'email' =>
  array (
    'type' => 'email',
    'maxlength' => '150',
  ),
)

没有本地PHP函数(据我所知)可以完全完成您的请求。

我已经写了2个我认为适合目的的方法:

function insertBefore($input, $index, $element) {
    if (!array_key_exists($index, $input)) {
        throw new Exception("Index not found");
    }
    $tmpArray = array();
    $originalIndex = 0;
    foreach ($input as $key => $value) {
        if ($key === $index) {
            $tmpArray[] = $element;
            break;
        }
        $tmpArray[$key] = $value;
        $originalIndex++;
    }
    array_splice($input, 0, $originalIndex, $tmpArray);
    return $input;
}

function insertAfter($input, $index, $element) {
    if (!array_key_exists($index, $input)) {
        throw new Exception("Index not found");
    }
    $tmpArray = array();
    $originalIndex = 0;
    foreach ($input as $key => $value) {
        $tmpArray[$key] = $value;
        $originalIndex++;
        if ($key === $index) {
            $tmpArray[] = $element;
            break;
        }
    }
    array_splice($input, 0, $originalIndex, $tmpArray);
    return $input;
}

虽然速度更快，而且可能更节省内存，但这只适用于不需要维护数组键的地方。

如果你确实需要维护密钥，下面的方法会更合适;

function insertBefore($input, $index, $newKey, $element) {
    if (!array_key_exists($index, $input)) {
        throw new Exception("Index not found");
    }
    $tmpArray = array();
    foreach ($input as $key => $value) {
        if ($key === $index) {
            $tmpArray[$newKey] = $element;
        }
        $tmpArray[$key] = $value;
    }
    return $input;
}

function insertAfter($input, $index, $newKey, $element) {
    if (!array_key_exists($index, $input)) {
        throw new Exception("Index not found");
    }
    $tmpArray = array();
    foreach ($input as $key => $value) {
        $tmpArray[$key] = $value;
        if ($key === $index) {
            $tmpArray[$newKey] = $element;
        }
    }
    return $tmpArray;
}

这可以通过array_splice完成，但是，当插入数组或使用字符串键时，array_splice会失败。我写了一个函数来处理所有情况:

function array_insert(&$arr, $index, $val)
{
    if (is_string($index))
        $index = array_search($index, array_keys($arr));
    if (is_array($val))
        array_splice($arr, $index, 0, [$index => $val]);
    else
        array_splice($arr, $index, 0, $val);
}

$a = array(1, 2, 3, 4);
$b = array_merge(array_slice($a, 0, 2), array(5), array_slice($a, 2));
// $b = array(1, 2, 5, 3, 4)

这也是一个有效的解决方案:

function array_insert(&$array,$element,$position=null) {
  if (count($array) == 0) {
    $array[] = $element;
  }
  elseif (is_numeric($position) && $position < 0) {
    if((count($array)+position) < 0) {
      $array = array_insert($array,$element,0);
    }
    else {
      $array[count($array)+$position] = $element;
    }
  }
  elseif (is_numeric($position) && isset($array[$position])) {
    $part1 = array_slice($array,0,$position,true);
    $part2 = array_slice($array,$position,null,true);
    $array = array_merge($part1,array($position=>$element),$part2);
    foreach($array as $key=>$item) {
      if (is_null($item)) {
        unset($array[$key]);
      }
    }
  }
  elseif (is_null($position)) {
    $array[] = $element;
  }  
  elseif (!isset($array[$position])) {
    $array[$position] = $element;
  }
  $array = array_merge($array);
  return $array;
}

获奖者: http://binarykitten.com/php/52-php-insert-element-and-shift.html

要将元素插入到具有字符串键的数组中，您可以这样做:

/* insert an element after given array key
 * $src = array()  array to work with
 * $ins = array() to insert in key=>array format
 * $pos = key that $ins will be inserted after
 */ 
function array_insert_string_keys($src,$ins,$pos) {

    $counter=1;
    foreach($src as $key=>$s){
        if($key==$pos){
            break;
        }
        $counter++;
    } 

    $array_head = array_slice($src,0,$counter);
    $array_tail = array_slice($src,$counter);

    $src = array_merge($array_head, $ins);
    $src = array_merge($src, $array_tail);

    return($src); 
}