show the data in dropdown fetched from database using laravel 8 - laravel

Question

i have to show the category values in dropdown in product form,the given code is from my view,the error is undefined $categories.this is my first code in laravel i dont know how to make changings in other files.which variable is used in foreach?or i have to create new function in ProductController?
<form action="/upload_product" method="post">
#csrf
<label>Choose Categories</label>
<select name="category_id" id="category" class="category">
<option disable selected>--select category--</option>
#foreach($categories as $item)
<option value="{{ $item->id }}">{{ $item->name}}</option>
#endforeach
</select>
<input type="text" name="name" placeholder="name">
<input type="number" name="sale_price" placeholder="sale_price">
</form>
Model Product.php
class Product extends Model
{
use HasFactory;
protected $table = 'products';
public $timestamps = true;
public function category(){
return $this->belongsTo('App\Models\Category');
}
}
Model Category.php
class Category extends Model
{
use HasFactory;
public $fillable = [ 'name' ];
protected $dates = [ 'deleted_at' ];
public $timestamps = true;
public function products (){
return $this->hasMany('App\Models\Product');
}
}
ProductController.php
<?php
namespace App\Http\Controllers;
use App\Models\Product;
use App\Models\Category;
use Illuminate\Http\Request;
class ProductController extends Controller
{
public function index()
{
$products = Product::all();
return view('products/index', ['products'=>$products]);
}
public function view()
{
$products = Product::with('category')->get();
$categories = Category::with('products')->get();
return view ('product.view')-> with([
'products' => $products,
'categories' => $categories,
]);
}

Answer 1

You have to use like below
public function index(){
$products = Product::all();
$categories = Category::with('products')->get();
return view('products.index', compact('products','categories'));
}

Answer 2

You don't have $categories in your index file.
Based on the index method, you're sendig just products:
public function index()
{
$products = Product::all();
return view('products/index', ['products'=>$products]);
}
So add categories too.

Answer 3

public function index()
{
$products = Product::get();
return view('products/index', ['products'=>$products]);
}

Answer 4

you can do this in three ways
public function index(){
$products = Product::all();
$categories = Category::with('products')->get();
return view('products.index', compact('products','categories'));
}
public function index(){
$products = Product::all();
$categories = Category::with('products')->get();
return view('products.index')->with(['products'=>$products,'categories'=>$categories]));
}
public function index(){
$data['products'] = Product::all();
$data['categories'] = Category::with('products')->get();
return view('products.index',$data);
}