PHP编码技巧：实现高效的商品多规格SKU功能

$sku = [
    '颜色' => ['红色', '蓝色', '绿色'],
    '尺寸' => ['S', 'M', 'L'],
    '材质' => ['棉', '丝绸']
];

function generateSku($sku)
{
    $result = [];
    $keys = array_keys($sku);
    $total = count($keys);
    $counts = array_map('count', $sku);
    $currentIndexes = array_fill(0, $total, 0);

    while (true) {
        $currentResult = [];
        for ($i = 0; $i < $total; $i++) {
            $currentResult[$keys[$i]] = $sku[$keys[$i]][$currentIndexes[$i]];
        }
        $result[] = $currentResult;

        $currentIndexes[0]++;
        for ($i = 0; $i < $total; $i++) {
            if ($currentIndexes[$i] >= $counts[$i]) {
                $currentIndexes[$i] = 0;
                if ($i < $total - 1) {
                    $currentIndexes[$i + 1]++;
                }
            }
        }

        if ($currentIndexes[$total - 1] >= $counts[$total - 1]) {
            break;
        }
    }

    return $result;
}

class Product
{
    public $sku;
    
    public function __construct()
    {
        $this->sku = [
            '颜色' => ['红色', '蓝色', '绿色'],
            '尺寸' => ['S', 'M', 'L'],
            '材质' => ['棉', '丝绸']
        ];
    }
}

$product = new Product();
$skus = generateSku($product->sku);

foreach ($skus as $sku) {
    // 在此处进行操作，比如将SKU存储到数据库中
}