更简洁的方法(基于使用的流动性和更少的代码)。

/**
 * Insert data at position given the target key.
 *
 * @param array $array
 * @param mixed $target_key
 * @param mixed $insert_key
 * @param mixed $insert_val
 * @param bool $insert_after
 * @param bool $append_on_fail
 * @param array $out
 * @return array
 */
function array_insert(
    array $array, 
    $target_key, 
    $insert_key, 
    $insert_val = null,
    $insert_after = true,
    $append_on_fail = false,
    $out = [])
{
    foreach ($array as $key => $value) {
        if ($insert_after) $out[$key] = $value;
        if ($key == $target_key) $out[$insert_key] = $insert_val;
        if (!$insert_after) $out[$key] = $value;
    }

    if (!isset($array[$target_key]) && $append_on_fail) {
        $out[$insert_key] = $insert_val;
    }

    return $out;
}

用法:

$colors = [
    'blue' => 'Blue',
    'green' => 'Green',
    'orange' => 'Orange',
];

$colors = array_insert($colors, 'blue', 'pink', 'Pink');

die(var_dump($colors));

$list = array(
'Tunisia' => 'Tunis',
'Germany' => 'Berlin',
'Italy' => 'Rom',
'Egypt' => 'Cairo'
);
$afterIndex = 2;
$newVal= array('Palestine' => 'Jerusalem');

$newList = array_merge(array_slice($list,0,$afterIndex+1), $newVal,array_slice($list,$afterIndex+1));

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)
    );

这可以通过array.splice()来实现。请注意，array_splice或array_merge不会为关联数组保留键。因此使用array_slice和'+'操作符来连接两个数组。

详情请点击这里

$array_1 = array(
    '0' => 'zero',
    '1' => 'one',
    '2' => 'two',
    '3' => 'three',
  );
  
  $array_2 = array(
    'zero'  => '0',
    'one'   => '1',
    'two'   => '2',
    'three' => '3',
  );
  $index = 2;
  $finalArray = array_slice($array_1, 0, $index, true) +
                $array2  +
                array_slice($array_2, $index, NULL, true);
print_r($finalArray);
/*
Array
(
    [0] => zero
    [1] => one
    [10] => grapes
    [z] => mangoes
    [two] => 2
    [three] => 3
)
*/

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
)

以下是我的看法:

/**
 * 
 * Insert an element after an index in an array
 * @param array $array  
 * @param string|int $key 
 * @param mixed $value
 * @param string|int $offset
 * @return mixed
 */
function array_splice_associative($array, $key, $value, $offset) {
    if (!is_array($array)) {
        return $array;
    }
    if (array_key_exists($key, $array)) {
        unset($array[$key]);
    }
    $return = array();
    $inserted = false;
    foreach ($array as $k => $v) {
        $return[$k] = $v;
        if ($k == $offset && !$inserted) {
            $return[$key] = $value;
            $inserted = true;
        }
    }
    if (!$inserted) {
        $return[$key] = $value;
    }


    return $return;
}