Question

我在我的项目中得到了这段代码，但我对它不满意，因为同样的var声明正在重复。有没有更好的方法来处理它？</ p>

if (type == 1) {
    var addressId = data.address.BillingAddress.id;
    var addressTitle = data.address.BillingAddress.title;
    var $select = $('.billingAddressId');
    var $notification = $('.billingNotification');
} else {
    var addressId = data.address.DeliveryAddress.id;
    var addressTitle= data.address.DeliveryAddress.title;
    var $select = $('.deliveryAddressId');
    var $notification = $('.shippingNotification');
}

Answer 1

为什么不在if-else阻止

之前声明它们

var addressId, addressTitle, $select, $notification;
if ( type == 1 ) {
     addressId = data.address.BillingAddress.id;
     addressTitle = data.address.BillingAddress.title;
     $select = $('.billingAddressId');
     $notification = $('.billingNotification');
} else {
     addressId = data.address.DeliveryAddress.id;
     addressTitle= data.address.DeliveryAddress.title;
     $select = $('.deliveryAddressId');
     $notification = $('.shippingNotification');
}

Answer 2

恕我直言，没有必要这样做。你会添加4行不必要的代码。

利用允许您执行此操作的Javascript，并保持原样。

Answer 3

您可以使用动态属性：

var addressId = data.address[type==1 ? "BillingAddress" : "DeliveryAddress"].id,
    addressTitle = data.address[type==1 ? "BillingAddress" : "DeliveryAddress"].title,
    $select = $(type==1 ? '.billingAddressId' : '.deliveryAddressId'),
    $notification = $(type==1 ? '.billingNotification' : '.shippingNotification');

Answer 4

您可以放弃if并使用short circuit evaluation：

var addressId = type === 1 && addressId = data.address.BillingAddress.id 
                           || data.address.DeliveryAddress.id;
/** ...etc **/

或使用ternary operator：

var addressId = type === 1 ? addressId = data.address.BillingAddress.id 
                           : data.address.DeliveryAddress.id;
/** ...etc **/

Answer 5

 var addressId = "";
var addressTitle ="";
var $select = "";
var $notification="";
if (type == 1) {
               addressId = data.address.BillingAddress.id;
                addressTitle = data.address.BillingAddress.title;
                $select = $('.billingAddressId');
                $notification = $('.billingNotification');
            } else {
                addressId = data.address.DeliveryAddress.id;
                addressTitle= data.address.DeliveryAddress.title;
                $select = $('.deliveryAddressId');
                $notification = $('.shippingNotification');
            }

Answer 6

在外部作用域中声明变量，以便您可以在块内访问它们。

var addressId = "";
var addressTitle = "";
var $select="";
var $notification="";

if (type == 1) {
    addressId = data.address.BillingAddress.id;
    addressTitle = data.address.BillingAddress.title;
    $select = $('.billingAddressId');
    $notification = $('.billingNotification');
} else {
    addressId = data.address.DeliveryAddress.id;
    addressTitle= data.address.DeliveryAddress.title;
    $select = $('.deliveryAddressId');
    $notification = $('.shippingNotification');
}

在if / else中是否有更好的变量声明方法

6 个答案: