你知道Laravel Collection的实际使用场景有哪些吗？

<?php // 引入package require __DIR__ . '/vendor/autoload.php';  $orders = [[     'id'            =>      1,     'user_id'       =>      1,     'number'        =>      '13908080808',     'status'        =>      0,     'fee'           =>      10,     'discount'      =>      44,     'order_products'=> [         ['order_id'=>1,'product_id'=>1,'param'=>'6寸','price'=>555.00,'product'=>['id'=>1,'name'=>'蛋糕名称','images'=>[]]],         ['order_id'=>1,'product_id'=>1,'param'=>'7寸','price'=>333.00,'product'=>['id'=>1,'name'=>'蛋糕名称','images'=>[]]],     ], ]];

$sum = 0; foreach ($orders as $order) {     foreach ($order['order_products'] as $item) {         $sum += $item['price'];     } } echo $sum;

$sum = collect($orders)->map(function($order){     return $order['order_products']; })->flatten(1)->map(function($order){     return $order['price']; })->sum();  echo $sum;

$sum = collect($orders)->flatMap(function($order){     return $order['order_products']; })->pluck('price')->sum(); echo $sum;

$sum = collect($orders)->flatMap(function($order){     return $order['order_products']; })->sum('price');

// 带格式化数组 $gates = [     'BaiYun_A_A17',     'BeiJing_J7',     'ShuangLiu_K203',     'HongQiao_A157',     'A2',     'BaiYun_B_B230' ];  // 新数组 $boards = [     'A17',     'J7',     'K203',     'A157',     'A2',     'B230' ];

$res = []; foreach($gates as $key => $gate) {     if(strpos($gate, '_') === false) {         $res[$key] = $gate;     }else{         $offset = strrpos($gate, '_') + 1;         $res[$key] = mb_substr($gate , $offset);     } } var_dump($res);

$res = collect($gates)->map(function($gate) {     $parts = explode('_', $gate);     return end($parts); });

$res = collect($gates)->map(function($gate) {     return collect(explode('_', $gate))->last(); })->toArray();

$opts = [         'http' => [                 'method' => 'GET',                 'header' => [                         'User-Agent: PHP'                 ]         ] ]; $context = stream_context_create($opts); $Events = json_decode(file_get_contents('http://api.github.com/users/0xAiKang/events', false, $context), true);

$eventTypes = []; // 事件类型 $score = 0; // 总得分 foreach ($events as $event) {     $eventTypes[] = $event['type']; }  foreach($eventTypes as $eventType) {     switch ($eventType) {         case 'PushEvent':         $score += 5;         break;         case 'CreateEvent':         $score += 4;         break;         case 'IssueEvent':         $score += 3;         break;         case 'IssueCommentEvent':         $score += 2;         break;         default:         $score += 1;         break;     } }

$score = $events->pluck('type')->map(function($eventType) {    switch ($eventType) {       case 'PushEvent':       return 5;       case 'CreateEvent':       return 4;       case 'IssueEvent':       return 3;       case 'IssueCommentEvent':       return 2;       default:       return 1;   } })->sum();

$score = $events->pluck('type')->map(function($eventType) {    return collect([        'PushEvent'=> 5,        'CreateEvent'=> 4,        'IssueEvent'=> 3,        'IssueCommentEvent'=> 2    ])->get($eventType, 1); // 如果不存在则默认等于1 })->sum();

class GithubScore {     private $events;      private function __construct($events){         $this->events = $events;     }      public static function score($events) {         return (new static($events))->scoreEvents();     }      private function scoreEvents() {         return $this->events->pluck('type')->map(function($eventType){             return $this->lookupEventScore($eventType, 1);         })->sum();     }      public function lookupEventScore($eventType, $default_value) {        return collect([            'PushEvent'=> 5,            'CreateEvent'=> 4,            'IssueEvent'=> 3,            'IssueCommentEvent'=> 2        ])->get($eventType, $default_value); // 如果不存在则默认等于1     } }  var_dump(GithubScore::score($events));

$messages = [     'Should be working now for all Providers.',     'If you see one where spaces are in the title let me know.',     'But there should not have blank in the key of config or .env file.' ];  // 格式化之后的结果 - Should be working now for all Providers. n - If you see one where spaces are in the title let me know. n - But there should not have blank in the key of config or .env file.

$comment = '- ' . array_shift($messages); foreach ($messages as $message) {     $comment .= "n -  ${message}"; } var_dump($comment);

$comment = collect($messages)->map(function($message){     return '- ' . $message; })->implode("n"); var_dump($comment);

$lastYear = [     6345.75,     9839.45,     7134.60,     9479.50,     9928.0,     8652.00,     7658.40,     10245.40,     7889.40,     3892.40,     3638.40,     2339.40 ];  $thisYear = [     6145.75,     6895.00,     3434.00,     9349350,     9478.60,     7652.80,     4758.40,     10945.40,     3689.40,     8992.40,     7588.40,     2239.40 ];

$profit = []; foreach($thisYear as $key => $monthly){     $profit[$key] = $monthly - $lastYear[$key]; } var_dump($profit);

$profit = collect($thisYear)->zip($lastYear)->map(function($monthly){     return $monthly->first() - $monthly->last(); });

$employees = [     [         'name' => 'example',         'email' => 'example@exmaple.com',         'company' => 'example Inc.'     ],     [         'name' => 'Lucy',         'email' => 'lucy@example.com',         'company' => 'ibm Inc.'     ],     [         'name' => 'Taylor',         'email' => 'toylor@laravel.com',         'company'=>'Laravel Inc.'     ] ];  // 格式化之后的结果 $lookup = [     'example' => 'example@example.com',     'Lucy' => ‘lucy@example.com’,     'Taylor'=> 'toylor@laravel.com' ];

$emails = []; foreach ($employees as $key => $value) {     $emails[$value['name']] = $value['email']; }

$emails = collect($employees)->reduce(function($emailLookup, $employee){     $emailLookup[$employee['name']] = $employee['email'];     return $emailLookup; },[]);

$emails = collect($employees)->pluck('name', 'email');