PHP foreach() 在数组中包含数组？
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PHP foreach() with arrays within arrays?
提问by Bojangles
I want to call a function on each element in an array. This is obviously very easy with a foreach(), but where I start breaking down is when arrays contain arrays. Can someone help me out with a function that will execute some code for every key -> value pair from a set of arrays within arrays. The depth could, in theory, be infinite, but a good limit would be 3 iterations (array in array in array) if recursion couldn't work.
我想对数组中的每个元素调用一个函数。使用 a 显然很容易foreach()，但我开始分解的地方是数组包含数组时。有人可以帮我解决一个函数，该函数将为数组中的一组数组中的每个键 -> 值对执行一些代码。理论上，深度可以是无限的，但如果递归不起作用，一个好的限制是 3 次迭代（数组中的数组中的数组）。
An example array would be one taken from $_POST below:
一个示例数组是从下面的 $_POST 中获取的一个：
Array
(
[languages] => Array
(
[0] => php
[1] => mysql
[2] => inglip
)
[rates] => Array
(
[incall] => Array
(
[1hr] => 10
)
[outcall] => Array
(
[1hr] => 10
)
)
)
Just to make sure, what I want to do is run a piece of code (a function) that is passed every 'end node' in the array structure, so in the example above, it would be called when...
只是为了确保，我想要做的是运行一段代码（一个函数），该代码传递给数组结构中的每个“结束节点”，因此在上面的示例中，它将在...
[0] => php [1] => mysql [2] => inglip [1hr] => 10 [1hr] => 10
... is found.
……被发现了。
Thanks for any help,
谢谢你的帮助，
James
詹姆士
回答by Gordon
That's a perfect job for Iterators:
这是Iterators的完美工作：
$iterator = new RecursiveIteratorIterator(new RecursiveArrayIterator($array));
foreach($iterator as $key => $value) {
echo "$key => $value\n";
}
See Introduction to SPL Iteratorsand Live Demo on codepad
EDIT:the alternative would be array_walk_recursiveas show in Finbarr's answer below
回答by Finbarr
See array_walk_recursive- a PHP library function that recursively calls a user defined function against a provided array.
请参阅array_walk_recursive- 一个 PHP 库函数，它针对提供的数组递归调用用户定义的函数。
From PHP docs:
来自 PHP 文档：
<?php
$sweet = array('a' => 'apple', 'b' => 'banana');
$fruits = array('sweet' => $sweet, 'sour' => 'lemon');
function test_print($item, $key)
{
echo "$key holds $item\n";
}
array_walk_recursive($fruits, 'test_print');
?>
Output:
输出：
a holds apple
b holds banana
sour holds lemon
Note that Any key that holds an array will not be passed to the function..
请注意Any key that holds an array will not be passed to the function.。
EDIT: slightly less ugly example:
编辑：稍微不那么难看的例子：
<?php
$sweet = array('a' => 'apple', 'b' => 'banana');
$fruits = array('sweet' => $sweet, 'sour' => 'lemon');
array_walk_recursive($fruits, function ($item, $key) {
echo "$key holds $item\n";
});
?>
回答by Pascal MARTIN
Typically, in this kind of situation, you'll have to write a recursive function-- which will deal with an item if it's not an array ; and call itself on an item if it's an array.
通常，在这种情况下，您必须编写一个递归函数——如果它不是数组，它将处理一个项目；如果它是一个数组，则在一个项目上调用自己。
Here, you could have something like this :
在这里，你可以有这样的事情：
$arr = array(
'languages' => array(
'php', 'mysql', 'inglip',
),
'rates' => array(
'incall' => array('1hr' => 10),
'outcall' => array('1hr' => 10),
),
);
function recurse($item) {
foreach ($item as $key => $value) {
if (is_array($value)) {
recurse($value);
} else {
echo "$key : $value\n";
}
}
}
And calling this recursive function on your array :
并在您的数组上调用此递归函数：
recurse($arr);
Would get you :
会让你：
0 : php
1 : mysql
2 : inglip
1hr : 10
1hr : 10
回答by Jon
Here's a simple reusable implementation:
这是一个简单的可重用实现：
function recursive_foreach($array, $callback) {
foreach($array as $key => $value) {
if (is_array($value)) {
recursive_foreach($value, $callback);
}
else {
call_user_func($callback, $key, $value);
}
}
}
Where $callbackis a callback accepting two arguments: key and value. For example:
$callback接受两个参数的回调在哪里：键和值。例如：
recursive_foreach($array, function($k, $v) {
echo "$k => $v<br>";
});
回答by Josh Davis
I want to call a function on each element in an array. This is obviously very easy with a foreach()
我想对数组中的每个元素调用一个函数。使用 foreach() 显然很容易
If you want to run a function on every element of a deep array, you can use array_walk_recursive()
如果要对深数组的每个元素运行一个函数，可以使用array_walk_recursive()
array_walk_recursive($array, function($v, $k)
{
echo "$k => $v\n";
});
If you want to iterate over each element with foreach, you need a recursive iterator as mentionned previously.
如果你想用 迭代每个元素foreach，你需要一个前面提到的递归迭代器。
If you're not sure which one to use, go with foreach+ recursive iterator. It's easier to grasp for most people.
如果您不确定要使用哪个，请使用foreach+ 递归迭代器。大多数人更容易掌握。
回答by thaolt
function getEndNodes($input, $ret = array()) {
foreach ($input as $key => $value) {
if (!is_array($input[$key])) {
$ret[$key] = $value;
} else {
$ret = getEndNodes($input[$key],$ret);
}
}
return $ret;
}
// Usage:
$endNodes = getEndNodes($yourarray);
回答by bicccio
function traverseArray($array)
{
foreach($array as $key=>$value)
{
if(is_array($value))
{
traverseArray($value);
}else{
echo '['.$key.']'.' => '.$value.'<br />\n';
}
}
}
回答by Marc B
function array_spelunk($array = array()) {
foreach($array as $key => $node) {
if (is_array($node)) {
array_spelunk($node);
} else {
echo "[$key] [$node]\n";
}
}
}
array_spelunk($your_nested_array);
回答by Emil Vikstr?m
function recurse($element, $key = null) {
if(is_array($element)) {
foreach($element as $k => $v) {
recurse($v, $k);
}
}else{
//Do what you want here. $element is value, $key is the key
}
}
