OP. 的要求是保留键（保留键）而不是重叠（我认为覆盖）。在某些情况下，例如数字键是可能的，但如果是字符串键，它似乎是不可能的。
如果你使用array_merge()数字键总是会重新索引或重新编号。
如果使用array_replace()，array_replace_recursive()它将从右到左重叠或覆盖。第一个数组上具有相同键的值将被第二个数组替换。
如果您使用$array1 + $array2提到的评论，如果键相同，那么它将保留第一个数组的值但删除第二个数组。
自定义功能。
这是我刚刚为满足相同要求而编写的函数。您可以出于任何目的自由使用。
/**
* Array custom merge. Preserve indexed array key (numbers) but overwrite string key (same as PHP's `array_merge()` function).
*
* If the another array key is string, it will be overwrite the first array.<br>
* If the another array key is integer, it will be add to first array depend on duplicated key or not.
* If it is not duplicate key with the first, the key will be preserve and add to the first array.
* If it is duplicated then it will be re-index the number append to the first array.
*
* @param array $array1 The first array is main array.
* @param array ...$arrays The another arrays to merge with the first.
* @return array Return merged array.
*/
function arrayCustomMerge(array $array1, array ...$arrays): array
{
foreach ($arrays as $additionalArray) {
foreach ($additionalArray as $key => $item) {
if (is_string($key)) {
// if associative array.
// item on the right will always overwrite on the left.
$array1[$key] = $item;
} elseif (is_int($key) && !array_key_exists($key, $array1)) {
// if key is number. this should be indexed array.
// and if array 1 is not already has this key.
// add this array with the key preserved to array 1.
$array1[$key] = $item;
} else {
// if anything else...
// get all keys from array 1 (numbers only).
$array1Keys = array_filter(array_keys($array1), 'is_int');
// next key index = get max array key number + 1.
$nextKeyIndex = (intval(max($array1Keys)) + 1);
unset($array1Keys);
// set array with the next key index.
$array1[$nextKeyIndex] = $item;
unset($nextKeyIndex);
}
}// endforeach; $additionalArray
unset($item, $key);
}// endforeach;
unset($additionalArray);
return $array1;
}// arrayCustomMerge
测试。
<?php
$array1 = [
'cat',
'bear',
'fruitred' => 'apple',
3 => 'dog',
null => 'null',
];
$array2 = [
1 => 'polar bear',
20 => 'monkey',
'fruitred' => 'strawberry',
'fruityellow' => 'banana',
null => 'another null',
];
// require `arrayCustomMerge()` function here.
function printDebug($message)
{
echo '<pre>';
print_r($message);
echo '</pre>' . PHP_EOL;
}
echo 'array1: <br>';
printDebug($array1);
echo 'array2: <br>';
printDebug($array2);
echo PHP_EOL . '<hr>' . PHP_EOL . PHP_EOL;
echo 'arrayCustomMerge:<br>';
$merged = arrayCustomMerge($array1, $array2);
printDebug($merged);
assert($merged[0] == 'cat', 'array key 0 should be \'cat\'');
assert($merged[1] == 'bear', 'array key 1 should be \'bear\'');
assert($merged['fruitred'] == 'strawberry', 'array key \'fruitred\' should be \'strawberry\'');
assert($merged[3] == 'dog', 'array key 3 should be \'dog\'');
assert(array_search('another null', $merged) !== false, '\'another null\' should be merged.');
assert(array_search('polar bear', $merged) !== false, '\'polar bear\' should be merged.');
assert($merged[20] == 'monkey', 'array key 20 should be \'monkey\'');
assert($merged['fruityellow'] == 'banana', 'array key \'fruityellow\' should be \'banana\'');
结果。
array1:
Array
(
[0] => cat
[1] => bear
[fruitred] => apple
[3] => dog
[] => null
)
array2:
Array
(
[1] => polar bear
[20] => monkey
[fruitred] => strawberry
[fruityellow] => banana
[] => another null
)
---
arrayCustomMerge:
Array
(
[0] => cat
[1] => bear
[fruitred] => strawberry
[3] => dog
[] => another null
[4] => polar bear
[20] => monkey
[fruityellow] => banana
)