我这样做

    $slightly_damaged = array_merge(
        array_slice($slightly_damaged, 0, 4, true) + ["4" => "0.0"], 
        array_slice($slightly_damaged, 4, count($slightly_damaged) - 4, true)
    );

该函数支持:

数字键和关联键 在建立键之前或之后插入 如果key未建立，则附加到数组末尾

function insert_into_array( $array, $search_key, $insert_key, $insert_value, $insert_after_founded_key = true, $append_if_not_found = false ) {

        $new_array = array();

        foreach( $array as $key => $value ){

            // INSERT BEFORE THE CURRENT KEY? 
            // ONLY IF CURRENT KEY IS THE KEY WE ARE SEARCHING FOR, AND WE WANT TO INSERT BEFORE THAT FOUNDED KEY
            if( $key === $search_key && ! $insert_after_founded_key )
                $new_array[ $insert_key ] = $insert_value;

            // COPY THE CURRENT KEY/VALUE FROM OLD ARRAY TO A NEW ARRAY
            $new_array[ $key ] = $value;

            // INSERT AFTER THE CURRENT KEY? 
            // ONLY IF CURRENT KEY IS THE KEY WE ARE SEARCHING FOR, AND WE WANT TO INSERT AFTER THAT FOUNDED KEY
            if( $key === $search_key && $insert_after_founded_key )
                $new_array[ $insert_key ] = $insert_value;

        }

        // APPEND IF KEY ISNT FOUNDED
        if( $append_if_not_found && count( $array ) == count( $new_array ) )
            $new_array[ $insert_key ] = $insert_value;

        return $new_array;

    }

用法:

    $array1 = array(
        0 => 'zero',
        1 => 'one',
        2 => 'two',
        3 => 'three',
        4 => 'four'
    );

    $array2 = array(
        'zero'  => '# 0',
        'one'   => '# 1',
        'two'   => '# 2',
        'three' => '# 3',
        'four'  => '# 4'
    );

    $array3 = array(
        0 => 'zero',
        1 => 'one',
       64 => '64',
        3 => 'three',
        4 => 'four'
    );


    // INSERT AFTER WITH NUMERIC KEYS
    print_r( insert_into_array( $array1, 3, 'three+', 'three+ value') );

    // INSERT AFTER WITH ASSOC KEYS
    print_r( insert_into_array( $array2, 'three', 'three+', 'three+ value') );

    // INSERT BEFORE
    print_r( insert_into_array( $array3, 64, 'before-64', 'before-64 value', false) );

    // APPEND IF SEARCH KEY ISNT FOUNDED
    print_r( insert_into_array( $array3, 'undefined assoc key', 'new key', 'new value', true, true) );

结果:

Array
(
    [0] => zero
    [1] => one
    [2] => two
    [3] => three
    [three+] => three+ value
    [4] => four
)
Array
(
    [zero] => # 0
    [one] => # 1
    [two] => # 2
    [three] => # 3
    [three+] => three+ value
    [four] => # 4
)
Array
(
    [0] => zero
    [1] => one
    [before-64] => before-64 value
    [64] => 64
    [3] => three
    [4] => four
)
Array
(
    [0] => zero
    [1] => one
    [64] => 64
    [3] => three
    [4] => four
    [new key] => new value
)

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。

这里有一个你可以使用的简单函数。只要插进去就行了。

这是按索引插入，而不是按值插入。

您可以选择传递该数组，或者使用已经声明的数组。

较新的、较短的版本:

   function insert($array, $index, $val)
   {
       $size = count($array); //because I am going to use this more than one time
       if (!is_int($index) || $index < 0 || $index > $size)
       {
           return -1;
       }
       else
       {
           $temp   = array_slice($array, 0, $index);
           $temp[] = $val;
           return array_merge($temp, array_slice($array, $index, $size));
       }
   }

更老、更长的版本:

  function insert($array, $index, $val) { //function decleration
    $temp = array(); // this temp array will hold the value 
    $size = count($array); //because I am going to use this more than one time
    // Validation -- validate if index value is proper (you can omit this part)       
        if (!is_int($index) || $index < 0 || $index > $size) {
            echo "Error: Wrong index at Insert. Index: " . $index . " Current Size: " . $size;
            echo "<br/>";
            return false;
        }    
    //here is the actual insertion code
    //slice part of the array from 0 to insertion index
    $temp = array_slice($array, 0, $index);//e.g index=5, then slice will result elements [0-4]
    //add the value at the end of the temp array// at the insertion index e.g 5
    array_push($temp, $val);
    //reconnect the remaining part of the array to the current temp
    $temp = array_merge($temp, array_slice($array, $index, $size)); 
    $array = $temp;//swap// no need for this if you pass the array cuz you can simply return $temp, but, if u r using a class array for example, this is useful. 
  
     return $array; // you can return $temp instead if you don't use class array
}

使用的例子:

//1
$result = insert(array(1,2,3,4,5),0, 0);
echo "<pre>";
echo "<br/>";
print_r($result);
echo "</pre>";
//2
$result = insert(array(1,2,3,4,5),2, "a");
echo "<pre>";
print_r($result);
echo "</pre>";
//3
$result = insert(array(1,2,3,4,5) ,4, "b");
echo "<pre>";
print_r($result);
echo "</pre>";
//4
$result = insert(array(1,2,3,4,5),5, 6);
echo "<pre>";
echo "<br/>";
print_r($result);
echo "</pre>";

预期结果:

//1
Array
(
    [0] => 0
    [1] => 1
    [2] => 2
    [3] => 3
    [4] => 4
    [5] => 5
)
//2
Array
(
    [0] => 1
    [1] => 2
    [2] => a
    [3] => 3
    [4] => 4
    [5] => 5
)
//3
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => b
    [5] => 5
)

//4
Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
)

Array_slice()可以用来提取数组的部分，联合数组操作符(+)可以重新组合这些部分。

$res = array_slice($array, 0, 3, true) +
    array("my_key" => "my_value") +
    array_slice($array, 3, count($array)-3, true);

这个例子:

$array = array(
  'zero'  => '0',
  'one'   => '1',
  'two'   => '2',
  'three' => '3',
);
$res = array_slice($array, 0, 3, true) +
    array("my_key" => "my_value") +
    array_slice($array, 3, count($array) - 1, true) ;
print_r($res);

给:

Array
(
    [zero] => 0
    [one] => 1
    [two] => 2
    [my_key] => my_value
    [three] => 3
)

对于第一个数组，使用array_splice():

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

array_splice($array_1, 3, 0, 'more');
print_r($array_1);

输出:

Array(
    [0] => zero
    [1] => one
    [2] => two
    [3] => more
    [4] => three
)

对于第二个，没有顺序，所以你只需要做:

$array_2['more'] = '2.5';
print_r($array_2);

把钥匙按你想要的排序。