Flatten Transformed Collections with flatMap()

Use flatMap() to map over a collection and collapse the nested array result into a flat collection in a single operation.

Mapping over a collection where callbacks return sub-arrays creates nested array structures. Combining map() and collapse() into flatMap() simplifies transformations.

use App\Models\User;

// Maps over users and flattens all roles into a single flat collection
$roles = $users->flatMap(fn ($user) => $user->roles);

• Combines map() transformation and collapse() flattening in a single call
• Flattens nested array structures returned by mapping callbacks
• Keeps collection pipeline code concise