如何在laravel中从关系表中获取计数？

public function posts()
{
    return $this->belongsToMany(Post::class);
}

$users = User::withCount('posts')->get();

foreach ($users as $user) {
    echo $user->name . ' has ' . $user->posts_count . ' posts.';
}

$users = User::withCount(['posts' => function ($query) {
    $query->having('posts_count', '>=', 5);
}])->get();

foreach ($users as $user) {
    echo $user->name . ' has ' . $user->posts_count . ' posts.';
}