基于this snippet, 检查购物车中的数量是否为最大值：

add_filter( \'woocommerce_quantity_input_args\', \'jk_woocommerce_quantity_input_args\', 10, 2 );
function jk_woocommerce_quantity_input_args( $args, $product ) {
    $args[\'max_value\'] = 10; // Maximum value
    return $args;
}

我试图添加一个条件，即如果项目onsale 等于的值SESSION 变量：

add_filter( \'woocommerce_quantity_input_args\', \'jk_woocommerce_quantity_input_args\', 10, 2 );
function jk_woocommerce_quantity_input_args( $args, $product ) { 
    $onsale = $product->is_on_sale();
    if ( ( $_SESSION[\'odertype\'] = \'local_delivery\' ) && $onsale ) {
        $args[\'max_value\'] = 10; // Maximum value
        return $args;
    }
}

不幸的是，它看起来像IF 语句不起作用，因为即使未设置会话变量，也会应用筛选器！

function jk_woocommerce_quantity_input_args( $args, $product ) { 
    if (
        isset( $_SESSION[\'ordertype\'] ) && // Never assume an array index exists
        $_SESSION[\'ordertype\'] == \'local_delivery\' && // Note == "same as" operator, not = "assign"
        $product->is_on_sale()
    ) {
        $args[\'max_value\'] = 10; // Maximum value
    }

    // Always return args for other filters/sanity
    return $args;
}