我必须使用un函数来查找数组中的每个元素。所以我修改了Jakub truneeek的函数如下:

function search_in_array_r($needle, $array) {
    $found = array();
    foreach ($array as $key => $val) {
        if ($val[1] == $needle) {
            array_push($found, $val[1]);
        }
    }
    if (count($found) != 0)
        return $found;
    else
        return null;
}

如果问题，即。

$a = [
     [
       "_id" => "5a96933414d48831a41901f2",
       "discount_amount" => 3.29,
       "discount_id" => "5a92656a14d488570c2c44a2",
     ],
     [
       "_id" => "5a9790fd14d48879cf16a9e8",
       "discount_amount" => 4.53,
       "discount_id" => "5a9265b914d488548513b122",
     ],
     [
       "_id" => "5a98083614d488191304b6c3",
       "discount_amount" => 15.24,
       "discount_id" => "5a92806a14d48858ff5c2ec3",
     ],
     [
       "_id" => "5a982a4914d48824721eafe3",
       "discount_amount" => 45.74,
       "discount_id" => "5a928ce414d488609e73b443",
     ],
    [
       "_id" => "5a982a4914d48824721eafe55",
       "discount_amount" => 10.26,
       "discount_id" => "5a928ce414d488609e73b443",
     ],
   ];

岁:

function searchForId($id, $array) {
    $did=0;
    $dia=0;
   foreach ($array as $key => $val) {
       if ($val['discount_id'] === $id) {
           $dia +=$val['discount_amount'];
           $did++;
       }
   }
    if($dia != '') {
        echo $dia;
        var_dump($did);
    }
   return null;
};
print_r(searchForId('5a928ce414d488609e73b443',$a));

/**
 * searches a simple as well as multi dimension array
 * @param type $needle
 * @param type $haystack
 * @return boolean
 */
public static function in_array_multi($needle, $haystack){
    $needle = trim($needle);
    if(!is_array($haystack))
        return False;

    foreach($haystack as $key=>$value){
        if(is_array($value)){
            if(self::in_array_multi($needle, $value))
                return True;
            else
               self::in_array_multi($needle, $value);
        }
        else
        if(trim($value) === trim($needle)){//visibility fix//
            error_log("$value === $needle setting visibility to 1 hidden");
            return True;
        }
    }

    return False;
}

只是分享，也许可以像这样。

if( ! function_exists('arraySearchMulti')){
function arraySearchMulti($search,$key,$array,$returnKey=false)
{
    foreach ($array as $k => $val) {
        if (isset($val[$key])) {
            if ((string)$val[$key] == (string)$search) {
                return ($returnKey ? $k : $val);
            }
        }else{
            return (is_array($val) ? arraySearchMulti($search,$key,$val,$returnKey) : null);
        }
    }
    return null;
}}

function searchForId($id, $array) {
   foreach ($array as $key => $val) {
       if ($val['uid'] === $id) {
           return $key;
       }
   }
   return null;
}

这是可行的。你应该这样称呼它:

$id = searchForId('100', $userdb);

重要的是要知道，如果你使用===运算符比较类型必须完全相同，在这个例子中，你必须搜索字符串或使用==代替===。

根据安哥拉人的回答。在PHP的后续版本(>= 5.5.0)中，可以使用一行程序。

$key = array_search('100', array_column($userdb, 'uid'));

这里是文档:http://php.net/manual/en/function.array-column.php。

这里有一个更好的解决方案，如果您从数据库或多维数组中提取数据

多维数组的例子:

$records = array(
            array(
                'id' => 2135,
                'first_name' => 'John',
                'last_name' => 'Doe',
            ),
            array(
                'id' => 3245,
                'first_name' => 'Sally',
                'last_name' => 'Smith',
            ),
            array(
                'id' => 5342,
                'first_name' => 'Jane',
                'last_name' => 'Jones',
            ),
            array(
                'id' => 5623,
                'first_name' => 'Peter',
                'last_name' => 'Doe',
            )
            );


            function search_user_by_name($name, $array) {
                             foreach ($array as $keys) {
                                 foreach ($keys as $key => $_user_record) {
                                     if ($_user_record == $name) {
                                         return [$key => $_user_record];//Return and array of user
                                     }
                                 }
                             }
                             return null;
                        }

调用函数:

$results = search_user_by_name('John', $records);
         print_r($results);
         

输出:Array ([first_name] => John)