У меня есть массив:
Array
(
[0] => Array
(
[tree_level] => 1
[id] => 1
[products_id] => 13
[categories_id] => 1
)
[1] => Array
(
[tree_level] => 2
[id] => 2
[products_id] => 13
[categories_id] => 2
)
[2] => Array
(
[tree_level] => 3
[id] => 3
[products_id] => 13
[categories_id] => 3
)
[3] => Array
(
[tree_level] => 1
[id] => 1
[products_id] => 25
[categories_id] => 1
)
[4] => Array
(
[tree_level] => 2
[id] => 2
[products_id] => 25
[categories_id] => 2
)
)
Можно ли выбрать максимальное значение tree_level для каждой группы с одинаковым products_id.
Результат должен быть таким:
Для products_id = 13 max tree_level = 3
а для products_id = 25 max tree_level = 2
Поскольку вы не предоставили никакого кода, я предоставил только часть моего;)
ЗАПОЛНИТЬ ПРОПУСКИ:
Мариуш: я заполняю пробелы
$aMaxCats = array(
array (
"tree_level" => 1,
"id" => 1,
"products_id" => 13,
"categories_id" => 1,
),
array (
"tree_level" => 2,
"id" => 2,
"products_id" => 13,
"categories_id" => 2,
),
array(
"tree_level" => 3,
"id" => 3,
"products_id" => 13,
"categories_id" => 3,
),
array (
"tree_level" => 1,
"id" => 1,
"products_id" => 25,
"categories_id" => 1,
),
array (
"tree_level" => 2,
"id" => 2,
"products_id" => 25,
"categories_id" => 2,
)
);
$newArray = array();
foreach( $aMaxCats as $product ) {
if( !isset( $product[ $product["products_id"] ] ) ) {
$newArray[ $product["products_id"] ] = array(
"product_id" =>$product["products_id"],
"categories_id"=>$product["categories_id"],
"max_tree_level" =>$product["tree_level"]
);
continue;
} else {
if( $newArray[$product["products_id"] ]["max_tree_level"] < $product["tree_level"] ) {
$newArray[$product["products_id"] ]["max_tree_level"] = $product["tree_level"];
}
}
}
// re-index array
$newArray = ___________ // google search for php reindex array
echo "<pre>";
var_dump( $newArray );
Может быть, что-то вроде DAT
$tmp=0;
foreach($arr as $key=>$value){
foreach($value as $k=>$data){
if($k=="categories_id"){
if($tmp<$data){
$tmp=$data;
}
}
}
}
echo $tmp;
Пытаться max()
функция
echo(max(tree_level" => 1,"id" => 1, "products_id" => 25,"categories_id" => 1,) . "<br>");
Подобно echo (max(1,2,3));
результат будет 3