假设我们有两个数组:
$array_1 = array(
'0' => 'zero',
'1' => 'one',
'2' => 'two',
'3' => 'three',
);
$array_2 = array(
'zero' => '0',
'one' => '1',
'two' => '2',
'three' => '3',
);
现在,我想在每个数组的第三个元素后插入数组('sample_key' => 'sample_value')。我该怎么做呢?
如果你不知道你想在位置3插入它,但你知道你想在后面插入它的键,在看到这个问题后,我想出了这个小函数。
/**
* Inserts any number of scalars or arrays at the point
* in the haystack immediately after the search key ($needle) was found,
* or at the end if the needle is not found or not supplied.
* Modifies $haystack in place.
* @param array &$haystack the associative array to search. This will be modified by the function
* @param string $needle the key to search for
* @param mixed $stuff one or more arrays or scalars to be inserted into $haystack
* @return int the index at which $needle was found
*/
function array_insert_after(&$haystack, $needle = '', $stuff){
if (! is_array($haystack) ) return $haystack;
$new_array = array();
for ($i = 2; $i < func_num_args(); ++$i){
$arg = func_get_arg($i);
if (is_array($arg)) $new_array = array_merge($new_array, $arg);
else $new_array[] = $arg;
}
$i = 0;
foreach($haystack as $key => $value){
++$i;
if ($key == $needle) break;
}
$haystack = array_merge(array_slice($haystack, 0, $i, true), $new_array, array_slice($haystack, $i, null, true));
return $i;
}
这里是一个代码板小提琴看到它的行动:http://codepad.org/5WlKFKfz
注意:array_splice()会比array_merge(array_slice())更有效,但这样你插入的数组的键就会丢失。叹息。
最简单的解决方案,如果你想在某个键后插入(一个元素或数组):
function array_splice_after_key($array, $key, $array_to_insert)
{
$key_pos = array_search($key, array_keys($array));
if($key_pos !== false){
$key_pos++;
$second_array = array_splice($array, $key_pos);
$array = array_merge($array, $array_to_insert, $second_array);
}
return $array;
}
如果你有:
$array = [
'one' => 1,
'three' => 3
];
$array_to_insert = ['two' => 2];
和执行:
$result_array = array_splice_after_key($array, 'one', $array_to_insert);
你会有:
Array (
['one'] => 1
['two'] => 2
['three'] => 3
)
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));
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
)
*/