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groupBy ​

不改变原集合，根据给定的键对集合内的项目进行分组。

php
collect([
  'key0' => ['product' => 'apples', 'price' => 10],
  'key1' => ['product' => 'apples', 'price' => 10],
  'key2' => ['product' => 'apples', 'price' => 20],
  'key3' => ['product' => 'apples', 'price' => 30],
  'key4' => ['product' => 'coconuts', 'price' => 40],
  'key5' => ['product' => 'coconuts', 'price' => 50],
])->groupBy('product');

/*
[
   "apples" => [
       ["product" => "apples", "price" => 10],
       ["product" => "apples", "price" => 10],
       ["product" => "apples", "price" => 20],
       ["product" => "apples", "price" => 30],
   ],
   "coconuts" => [
       ["product" => "coconuts", "price" => 40],
       ["product" => "coconuts", "price" => 50],
   ],
 ]
*/

默认情况下 key 将会被重置，通过传入第二个参数 true 保留 key。

php
collect([
  'key0' => ['product' => 'apples', 'price' => 10],
  'key1' => ['product' => 'apples', 'price' => 10],
  'key2' => ['product' => 'apples', 'price' => 20],
  'key3' => ['product' => 'apples', 'price' => 30],
  'key4' => ['product' => 'coconuts', 'price' => 40],
  'key5' => ['product' => 'coconuts', 'price' => 50],
])->groupBy('product', true); // 添加 true 参数，保留key

/*
[
   "apples" => [
       "key0" => ["product" => "apples", "price" => 10],
       "key1" => ["product" => "apples", "price" => 10],
       "key2" => ["product" => "apples", "price" => 20],
       "key3" => ["product" => "apples", "price" => 30]
   ], 
   "coconuts" => [
       "key4" => ["product" => "coconuts", "price" => 40],
       "key5" => ["product" => "coconuts", "price" => 50],
   ]
]
 */

除了传入一个字符串的「键」，还可以传入一个回调。该回调应该返回用来分组的键的值。

php
// 下面的示例如果使用 `code` 字段来分组的话得到的结果不是预期，可以通过回调函数稍作处理。
collect([
  ['code' => '123VG', 'name' => 'string1'],
  ['code' => '123-VG', 'name' => 'string2'],
  ['code' => '123 VG', 'name' => 'string3'],
])->groupBy(function ($element) {
  return str_replace(['-', ' '], [], $element['code']);
});

/*
[
   "123VG" => [
       ["code" => "123VG", "name" => "string1"],
       ["code" => "123-VG","name" => "string2"],
       ["code" => "123 VG","name" => "string3"],
   ],
]
 */

不改变原集合 ​

php
$collection = collect([
  ['code' => '123VG', 'name' => 'string1'],
  ['code' => '123-VG', 'name' => 'string2'],
  ['code' => '123 VG', 'name' => 'string3'],
]);

$newCollection = $collection->groupBy(fn ($element) => str_replace(['-', ' '], [], $element['code']));

$collection->dump();
$newCollection->dd();

/*
[
  ["code" => "123VG", "name" => "string1"]
  ["code" => "123-VG", "name" => "string2"]
  ["code" => "123 VG", "name" => "string3"]
]
[
  "123VG" => [
      [ "code" => "123VG", "name" => "string1"]
      [ "code" => "123-VG", "name" => "string2"]
      [ "code" => "123 VG", "name" => "string3"]
  ] 
]
*/

相关方法 ​