如何获取 Laravel 集合中元素的索引答案

【问题标题】：How to get index of element in Laravel collection如何获取 Laravel 集合中元素的索引
【发布时间】：2019-05-08 18:34:00
【问题描述】：

如何检索集合中元素的索引？我的代码：

$users = User::has('posts')->withCount('posts')->orderBy('posts_count')->take(50)->get();

if($users->contains(Auth::id())){
    //get the index of auth user id
 }

谢谢你的帮助

【问题讨论】：

标签： php mysql laravel collections eloquent

【解决方案1】：

可以使用集合search()方法：https://laravel.com/docs/5.7/collections#method-search

$users = User::has('posts')->withCount('posts')->orderBy('posts_count')->take(50)->get();

$userIndex = $users->search(function($user) {
    return $user->id === Auth::id();
});

请小心，因为索引可能为 0：

// DON'T do this
if($userIndex) {
    // this will get skipped if the user is the first one in the collection
}

// Do this instead
if($userIndex !== false) {
    // this will work
}

【讨论】：

【解决方案2】：

$users = User::has('posts')->withCount('posts')->orderBy('posts_count')->take(50)->get();

// this return a collection. So can do an if like this: $userIndex->count() > 0
$userIndex = $users->filter(function($user) {
    return $user->id === Auth::id()
});

【讨论】：