Challenge 1 — Solution

Task: Create two files, src/Shop/Product.php (namespace Shop; class
Product with a $name property) and src/Warehouse/Product.php (namespace
Warehouse; class Product with a $stockLevel property). In a third file,
use both classes with aliases via use ... as ... and create one
instance of each, demonstrating no naming collision occurs.

<?php
    // ---- src/Shop/Product.php ----
    // <?php
    //     namespace Shop;
    //
    //     class Product {
    //         public string $name;
    //
    //         public function __construct(string $name) {
    //             $this->name = $name;
    //         }
    //     }
    // ?>

    // ---- src/Warehouse/Product.php ----
    // <?php
    //     namespace Warehouse;
    //
    //     class Product {
    //         public int $stockLevel;
    //
    //         public function __construct(int $stockLevel) {
    //             $this->stockLevel = $stockLevel;
    //         }
    //     }
    // ?>

    // ---- index.php ----
    // use Shop\Product as ShopProduct;
    // use Warehouse\Product as WarehouseProduct;
    //
    // $listing = new ShopProduct("Wireless Mouse");
    // $stock = new WarehouseProduct(150);
    //
    // echo $listing->name . "<br>";
    // echo $stock->stockLevel . "<br>";

    // A single-file demonstration of the same underlying idea:
    namespace Shop { class Product { public function __construct(public string $name) {} } }
    namespace Warehouse { class Product { public function __construct(public int $stockLevel) {} } }
    namespace {
        use Shop\Product as ShopProduct;
        use Warehouse\Product as WarehouseProduct;

        $listing = new ShopProduct("Wireless Mouse");
        $stock = new WarehouseProduct(150);

        echo $listing->name . "<br>";
        echo $stock->stockLevel;
    }
?>


Output:
Wireless Mouse
150

Notes:
- Both classes are genuinely named Product, but their fully-qualified
  identities - Shop\Product and Warehouse\Product - are completely
  distinct, exactly as the chapter's own Logger example demonstrated.
- use Shop\Product as ShopProduct gives the class a shorter, unambiguous
  local alias within this one file, so "new ShopProduct(...)" reads
  cleanly without needing to write the full namespace every time.
- No fatal "Cannot redeclare class Product" error occurs, even though
  both classes share the identical short name - this is precisely the
  collision-avoidance benefit namespaces provide.