(PHP 5 >= 5.3.0, PHP 7, PHP 8)
array_replace_recursive — 使用传递的数组递归替换第一个数组的元素
$array1
, array $... = ?
) : array
array_replace_recursive() 使用后面数组元素的值替换数组 array1 的值。
如果一个键存在于第一个数组同时也存在于第二个数组，它的值将被第二个数组中的值替换。
如果一个键存在于第二个数组，但是不存在于第一个数组，则会在第一个数组中创建这个元素。
如果一个键仅存在于第一个数组，它将保持不变。
如果传递了多个替换数组，它们将被按顺序依次处理，后面的数组将覆盖之前的值。
array_replace_recursive() 是递归的：它将遍历数组并将相同的处理应用到数组的内部值。
如果第一个数组中的值是标量，它的值将被第二个数组中的值替换，它可能是一个标量或者数组。如果第一个数组和第二个数组中的值都是数组，array_replace_recursive() 函数将递归地替换它们各自的值。
array1替换该数组的值。
...可选项。包含要提取元素的数组。
返回一个数组。如果发生错误，将返回 null。
Example #1 array_replace_recursive() 范例
<?php
$base = array('citrus' => array( "orange") , 'berries' => array("blackberry", "raspberry"), );
$replacements = array('citrus' => array('pineapple'), 'berries' => array('blueberry'));
$basket = array_replace_recursive($base, $replacements);
print_r($basket);
$basket = array_replace($base, $replacements);
print_r($basket);
?>
以上例程会输出：
Array
(
[citrus] => Array
(
[0] => pineapple
)
[berries] => Array
(
[0] => blueberry
[1] => raspberry
)
)
Array
(
[citrus] => Array
(
[0] => pineapple
)
[berries] => Array
(
[0] => blueberry
)
)
Example #2 array_replace_recursive() 及其递归表现
<?php
$base = array('citrus' => array("orange") , 'berries' => array("blackberry", "raspberry"), 'others' => 'banana' );
$replacements = array('citrus' => 'pineapple', 'berries' => array('blueberry'), 'others' => array('litchis'));
$replacements2 = array('citrus' => array('pineapple'), 'berries' => array('blueberry'), 'others' => 'litchis');
$basket = array_replace_recursive($base, $replacements, $replacements2);
print_r($basket);
?>
以上例程会输出：
Array
(
[citrus] => Array
(
[0] => pineapple
)
[berries] => Array
(
[0] => blueberry
[1] => raspberry
)
[others] => litchis
)
It seemed to me that the first argument is passed by reference, so it will contain the results of this operation, but experiment shows that this is not true. The array value from the first argument is modified by each succeeding argument, and the result is returned to the caller. The array passed as the first argument is not modified.
Note that function will NOT replace a sub-tree from you $array1 if its value in $array2 is an empty array.
Even tho the key for this dimension is technically 'set'.
(I suppose it treats it as just another recursive level to dive in, finding no key to compare, backtracking while leaving this sub-tree alone)
For example:
$array1 = ['first' => ['second' => 'hello']];
$array2 = ['first' => []];
$result = array_replace_recursive($array1, $array2);
$result is still: ['first' => ['second' => 'hello']].
Note that the use of the word "replace" in the function's description is a bit misleading... as none of the parameters are passed by reference, it does not actually replace anything... this simply describes from which parameter the resulting values come.
If you came here looking for a function to recursively find and replace (scalar) values in an array (also recurses through objects):
<?php
define('RECURSIVE_REPLACE_MARKER', 'recursive_replace_r47yr74yr7623t74r3645236rtvghdcbnsgxbt67g5e21873891');
/**
* Recursively replaces scalar values in objects and arrays. The passed array or object is altered in place.
* @param mixed $data An object or array.
* @param mixed $find The scalar value to find.
* @param mixed $replace The value to replace with (need not be a scalar).
*/
function recursive_replace(&$data, $find, $replace){
if(is_array($data)) {
if (!isset($data[RECURSIVE_REPLACE_MARKER])) {
$data[RECURSIVE_REPLACE_MARKER] = TRUE;
foreach($data as $key=>$val) {
if(is_array($data[$key]) || is_object($data[$key])) {
recursive_replace($data[$key], $find, $replace);
}
else{
if($data[$key] === $find) {
$data[$key] = $replace;
}
}
}
unset($data[RECURSIVE_REPLACE_MARKER]);
}
}
elseif (is_object($data)) {
if (!isset($data->RECURSIVE_REPLACE_MARKER)) {
$data->RECURSIVE_REPLACE_MARKER = TRUE;
foreach($data as $key=>$val) {
if(is_array($data->$key) || is_object($data->$key)){
recursive_replace($data->$key, $find, $replace);
}else{
if($data->$key === $find) {
$data->$key = $replace;
}
}
}
unset($data->RECURSIVE_REPLACE_MARKER);
}
}
}
?>
This is a fairly concise version which does not rely on traditional recursion:
<?php
function array_replace_recursive($base, $replacements)
{
foreach (array_slice(func_get_args(), 1) as $replacements) {
$bref_stack = array(&$base);
$head_stack = array($replacements);
do {
end($bref_stack);
$bref = &$bref_stack[key($bref_stack)];
$head = array_pop($head_stack);
unset($bref_stack[key($bref_stack)]);
foreach (array_keys($head) as $key) {
if (isset($key, $bref) && is_array($bref[$key]) && is_array($head[$key])) {
$bref_stack[] = &$bref[$key];
$head_stack[] = $head[$key];
} else {
$bref[$key] = $head[$key];
}
}
} while(count($head_stack));
}
return $base;
}
?>
Nice that this function finally found its was to the PHP core! If you want to use it also with older PHP versions before 5.3.0, you can define it this way:
<?php
if (!function_exists('array_replace_recursive'))
{
function array_replace_recursive($array, $array1)
{
function recurse($array, $array1)
{
foreach ($array1 as $key => $value)
{
// create new key in $array, if it is empty or not an array
if (!isset($array[$key]) || (isset($array[$key]) && !is_array($array[$key])))
{
$array[$key] = array();
}
// overwrite the value in the base array
if (is_array($value))
{
$value = recurse($array[$key], $value);
}
$array[$key] = $value;
}
return $array;
}
// handle the arguments, merge one by one
$args = func_get_args();
$array = $args[0];
if (!is_array($array))
{
return $array;
}
for ($i = 1; $i < count($args); $i++)
{
if (is_array($args[$i]))
{
$array = recurse($array, $args[$i]);
}
}
return $array;
}
}
?>
I called this function array_merge_recursive_overwrite() in my older projects, but array_replace_recursive() sounds quite better while they do the same.
If you implemented such a compatible function before and don't want to refactor all your code, you can update it with the following snippet to use the native (and hopefully faster) implementation of PHP 5.3.0, if available. Just start your function with these lines:
<?php
// as of PHP 5.3.0 array_replace_recursive() does the work for us
if (function_exists('array_replace_recursive'))
{
return call_user_func_array('array_replace_recursive', func_get_args());
}
?>
This might help out people who don't have 5.3 running:
<?php
// Joins two or more arrays together recursively; key/value pairs of the first
// array are replaced with key/value pairs from the subsequent arrays. Any
// key/value pair not present in the first array is added to the final array
function array_join()
{
// Get array arguments
$arrays = func_get_args();
// Define the original array
$original = array_shift($arrays);
// Loop through arrays
foreach ($arrays as $array)
{
// Loop through array key/value pairs
foreach ($array as $key => $value)
{
// Value is an array
if (is_array($value))
{
// Traverse the array; replace or add result to original array
$original[$key] = array_join($original[$key], $array[$key]);
}
// Value is not an array
else
{
// Replace or add current value to original array
$original[$key] = $value;
}
}
}
// Return the joined array
return $original;
}
?>