如何在Laravel Eloquent Collection数组前添加键值对？

Question

I'm fetching something from database:

$foo = $this->fooRepository->all()->lists('name', 'id');

I get:

Collection {#506 ▼
  #items: array:9 [▼
    "9c436867-afe9-4234-a849-253aea4f602c" => "aaa"
    "d250102b-1370-40d0-99c5-7e5bfd0a15e4" => "sss"
    "7342f212-083b-458d-8af8-24986bbb627d" => "ddd"
    "029c53ce-dc16-49fd-8d83-9d8270d9ff37" => "fff"
    "3add6a37-72e2-4054-853e-9ed8addbf3ea" => "ggg"
    "28f5a9ac-014e-4f22-bda8-e2d5b1f48273" => "hhh"
    "94fccb2c-d732-4369-9bf7-78925797e578" => "jjj"
    "5b494994-93f0-406e-b420-aceb7b6111d7" => "kkk"
    "22a7824a-c6eb-45e7-b9c5-e40c134e3ac8" => "lll"
  ]
}

Perfect. This collection is later passed into Form::select to populate select / option dropdown.

I would like to prepend this collection with another key-value pair where key will be empty string and value will contain text like " Choose something ".

I can append:

$foo[''] = 'Choose something…';

so I get

Collection {#506 ▼
  #items: array:10 [▼
    "9c436867-afe9-4234-a849-253aea4f602c" => "aaa"
    "d250102b-1370-40d0-99c5-7e5bfd0a15e4" => "sss"
    "7342f212-083b-458d-8af8-24986bbb627d" => "ddd"
    "029c53ce-dc16-49fd-8d83-9d8270d9ff37" => "fff"
    "3add6a37-72e2-4054-853e-9ed8addbf3ea" => "ggg"
    "28f5a9ac-014e-4f22-bda8-e2d5b1f48273" => "hhh"
    "94fccb2c-d732-4369-9bf7-78925797e578" => "jjj"
    "5b494994-93f0-406e-b420-aceb7b6111d7" => "kkk"
    "22a7824a-c6eb-45e7-b9c5-e40c134e3ac8" => "lll"
    "" => "Choose something…"
  ]
}

but no idea how I can move it as the first element of the collection . I simply cannot use array_merge because I'm dealing with instance of Illuminate\\Database\\Eloquent\\Collection rather than array so this answer won't work.

Any hints? Thanks.

Answer 1

$foo = ['' => 'Choose something…'] + $foo->all();

If your $foo must be a collection instance, simply wrap it in a collection again:

$foo = collect(['' => 'Choose something…'] + $foo->all());

---

I submitted a PR to laravel to allow you to pass a key to prepend . If you're using Laravel 5.1.24 or newer, you can now do this:

$foo = $this->fooRepository->all()
            ->lists('name', 'id')
            ->prepend('Choose something…', '');

---

Later versions of Laravel have renamed the lists method to pluck . If you're using relatively modern version of Laravel, use pluck instead:

$foo = $this->fooRepository->all()
            ->pluck('name', 'id')
            ->prepend('Choose something…', '');

Answer 2

Try using ->prepend()

http://laravel.com/api/5.1/Illuminate/Database/Eloquent/Collection.html#method_prepend

 
 
 
  
  $foo->prepend('Choose Something')
 
  

---

This won't give the correct result. The index would be 0 instead of an empty string. Instead you could try something like this

 $foo = $foo->reverse()->put('Choose Something')->reverse() 

But using @Joseph Silber answer is probably better.