keyBy方法

以给定的键作为集合的键。如果多个项目具有相同的键，则只有最后一个项目会显示在新集合中。

$collection = collect([
    ['product_id' => 'prod-100', 'name' => 'desk'],
    ['product_id' => 'prod-200', 'name' => 'chair'],
]);

$keyed = $collection->keyBy('product_id');

$keyed->all();

/*
[
    'prod-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
    'prod-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
]
*/

也可以传入一个回调方法，回调返回的值会作为该集合的键

$keyed = $collection->keyBy(function ($item) {
    return strtoupper($item['product_id']);
});

$keyed->all();

/*
[
    'PROD-100' => ['product_id' => 'prod-100', 'name' => 'Desk'],
    'PROD-200' => ['product_id' => 'prod-200', 'name' => 'Chair'],
]
*/