How to validate array in Laravel?

Asterisk symbol (*) is used to check values in the array, not the array itself.

$validator = Validator::make($request->all(), [
    "names"    => "required|array|min:3",
    "names.*"  => "required|string|distinct|min:3",
]);

In the example above:

"names" must be an array with at least 3 elements,

values in the "names" array must be distinct (unique) strings, at least 3 characters long.

EDIT: Since Laravel 5.5 you can call validate() method directly on Request object like so:

$data = $request->validate([
    "name"    => "required|array|min:3",
    "name.*"  => "required|string|distinct|min:3",
]);

---

I have this array as my request data from a HTML+Vue.js data grid/table:

[0] => Array
    (
        [item_id] => 1
        [item_no] => 3123
        [size] => 3e
    )
[1] => Array
    (
        [item_id] => 2
        [item_no] => 7688
        [size] => 5b
    )

And use this to validate which works properly:

$this->validate($request, [
    '*.item_id' => 'required|integer',
    '*.item_no' => 'required|integer',
    '*.size'    => 'required|max:191',
]);

---

The recommended way to write validation and authorization logic is to put that logic in separate request classes. This way your controller code will remain clean.

You can create a request class by executing php artisan make:request SomeRequest.

In each request class's rules() method define your validation rules:

//SomeRequest.php
public function rules()
{
   return [
    "name"    => [
          'required',
          'array', // input must be an array
          'min:3'  // there must be three members in the array
    ],
    "name.*"  => [
          'required',
          'string',   // input must be of type string
          'distinct', // members of the array must be unique
          'min:3'     // each string must have min 3 chars
    ]
  ];
}

In your controller write your route function like this:

// SomeController.php
public function store(SomeRequest $request) 
{
  // Request is already validated before reaching this point.
  // Your controller logic goes here.
}

public function update(SomeRequest $request)
{
  // It isn't uncommon for the same validation to be required
  // in multiple places in the same controller. A request class
  // can be beneficial in this way.
}

Each request class comes with pre- and post-validation hooks/methods which can be customized based on business logic and special cases in order to modify the normal behavior of request class.

You may create parent request classes for similar types of requests (e.g. web and api) requests and then encapsulate some common request logic in these parent classes.

---

Little bit more complex data, mix of @Laran's and @Nisal Gunawardana's answers

[ 
   {  
       "foodItemsList":[
    {
       "id":7,
       "price":240,
       "quantity":1
                },
               { 
                "id":8,
                "quantity":1
               }],
        "price":340,
        "customer_id":1
   },
   {   
      "foodItemsList":[
    {
       "id":7,
       "quantity":1
    },
    { 
        "id":8,
        "quantity":1
    }],
    "customer_id":2
   }
]

The validation rule will be

 return [
            '*.customer_id' => 'required|numeric|exists:customers,id',
            '*.foodItemsList.*.id' => 'required|exists:food_items,id',
            '*.foodItemsList.*.quantity' => 'required|numeric',
        ];

---

You have to loop over the input array and add rules for each input as described here: Loop Over Rules

Here is a some code for ya:

$input = Request::all();
$rules = [];

foreach($input['name'] as $key => $val)
{
    $rules['name.'.$key] = 'required|distinct|min:3';
}

$rules['amount'] = 'required|integer|min:1';
$rules['description'] = 'required|string';

$validator = Validator::make($input, $rules);

//Now check validation:
if ($validator->fails()) 
{ 
  /* do something */ 
}

---

The below code working for me on array coming from ajax call .

  $form = $request->input('form');
  $rules = array(
            'facebook_account' => 'url',
            'youtube_account' => 'url',
            'twitter_account' => 'url',
            'instagram_account' => 'url',
            'snapchat_account' => 'url',
            'website' => 'url',
        );
        $validation = Validator::make($form, $rules);

        if ($validation->fails()) {
            return Response::make(['error' => $validation->errors()], 400);
        }

---

In my Case it works fine

$validator = Validator::make($request->all(), [
    "names" => "required|array|min:3",
    "*.names"=> "required|string|distinct|min:3",
]);

---