我想从不同的数组中获得最大的值。基本上，数组是从3个不同的网站填充的，我需要知道每个产品的最大tags和photos值是多少。
我有以下数组：
$data = array(
'domain1.com' => array(
'id1' => array(
'tags' => '5',
'photos' => '4',
),
'id2' => array(
'tags' => '8',
'photos' => '2',
),
'id3' => array(
'tags' => '6',
'photos' => '1',
),
),
'domain2.com' => array(
'id1' => array(
'tags' => '3',
'photos' => '1',
),
'id2' => array(
'tags' => '4',
'photos' => '9',
),
'id3' => array(
'tags' => '2',
'photos' => '0',
),
),
'domain3.com' => array(
'id1' => array(
'tags' => '7',
'photos' => '3',
),
'id2' => array(
'tags' => '9',
'photos' => '5',
),
'id3' => array(
'tags' => '2',
'photos' => '4',
),
),
);
我需要得到以下结果：
$data = array(
'id1' => array(
'tags' => '7',
'photos' => '4',
),
'id2' => array(
'tags' => '9',
'photos' => '9',
),
'id3' => array(
'tags' => '6',
'photos' => '4',
),
);
这可以通过一个简单的循环来解决：
$new = array();
foreach($data as $domain){
foreach($domain as $id => $_data){
foreach($_data as $elem => $value) {
if(!isset($new[$id][$elem]) || $value > $new[$id][$elem]){
$new[$id][$elem] = $value;
}
}
}
}
哪个返回：
Array
(
[id1] => Array
(
[tags] => 7
[photos] => 4
)
[id2] => Array
(
[tags] => 9
[photos] => 9
)
[id3] => Array
(
[tags] => 6
[photos] => 4
)
)
示例
最简单的方法是使用嵌套的foreach循环来迭代和捕获数据。如果在结果数组中找到更高的值，则会更新结果。
$results = [];
foreach ($data as $domain => $items) {
foreach ($items as $id => $elements) {
if (!isset($results[ $id ])) {
$results[ $id ] = [];
}
foreach ($elements as $tag => $value) {
if (!isset($results[ $id ][ $tag ]) || $value>$results[ $id ][ $tag ]) {
$results[ $id ][ $tag ] = $value;
}
}
}
}
print_r($results);