Undefined offset: 1 laravel

Question

i'm new to laravel I have a form with dynamic fields but when I create more than one dynamic field and click submit this error appears: Undefined offset: 1 but it's working with only one field. i saw who someone who used isset but i don't know how to use it in my case Can anyone tell me that why such error occurs in php

Controller :

   public function store(Request $request)

{   
    
    $data['invoice_no'] = $request->invoice_no;
        
    $data['last_invoice_no'] = $request->last_invoice_no;
    $data['devise'] = $request->devise;
    $data['customer_name'] = $request->customer_name;
    $data['customer_adress'] = $request->customer_adress;
    $data['invoice_no'] = $request->invoice_no;
    $data['invoice_date'] = $request->invoice_date;
  
    $data['company_adress'] = $request->company_adress;
    $data['company_name'] = $request->company_name;
    $data['company_phone'] = $request->company_phone;
    $data['poids_brut'] = $request->poids_brut;
    $data['poids_net'] = $request->poids_net;
    $data['livraison'] = $request->livraison;
    $data['incoterm'] = $request->incoterm;
    $data['payment_details'] = $request->payment_details;
    $data['sub_total'] = $request->sub_total;
    $data['shipping'] = $request->shipping;
    $data['total_due'] = $request->total_due;
    $data['created_by'] = (Auth::user()->name);

    $invoices = Invoices::create($data);

    $details_list = [];
    for ($i = 0; $i < count($request->categorie_id); $i++) {
       
                              
        $details_list[$i]['categorie_id'] = $request->categorie_id[$i];
        $details_list[$i]['product_id'] = $request->product_id[$i];
        $details_list[$i]['size_id'] = $request->size_id[$i];
        $details_list[$i]['quantity'] = $request->quantity[$i];
        $details_list[$i]['unit_price'] = $request->unit_price[$i];
        $details_list[$i]['total_price'] = $request->total_price[$i];
        $details_list[$i]['created_by'] = (Auth::user()->name);
   
               }

    $details = $invoices->details()->createMany($details_list);

    if ($details) {
        return redirect('/invoices')->with([
            'message' => __('la facture est créé avec succès'),
            'alert-type' => 'success'
        ]);
    } else {
        return redirect()->back()->with([
            'message' => __('la creation de facture a échoué'),
            'alert-type' => 'danger'
        ]);
    }
   

   }

Invoice Model :

class invoices extends Model
{
     protected $guarded=[];
    public function details()
    {
        return $this->hasMany(invoice_products::class, 'invoice_id', 'id');
    }
}

Invoice Products Model :

class invoice_products extends Model
{
    protected $guarded=[];

    public function invoice()
    {
        return $this->belongsTo(Invoices::class, 'invoice_id', 'id');
    }
}

Answer 1

Reason:

this error appears: Undefined offset: 1

You can find the explanation Here

Your Case:

for ($i = 0; $i < count($request->categorie_id); $i++) { $details_list[$i]['categorie_id'] = $request->categorie_id[$i];

Maybe (because we don't know what you are passing from your form) your $request->categorie_id does not have a key/index 1. So, in your for loop, it looks for $request->categorie_id[1] and failing throws the error Undefined offset: 1, which means the array $request->categorie_id[] does not have the key/index/offset 1.

Suggestion:

You can dd($request->all()); or dd($request->categorie_id); inside your store method to see what is inside to make sure it contains $request->categorie_id[] array with index 1