javascript - JS/ES6 : Undefined check on destructuring on a dynamic defined variable

Question

我正在使用一些基于动态数据的解构:

const {
        groupSku,
        parentGroupSKU,
        orderOriginationId,
        sku,
        quantity,
        partialShip,
        categoryID,
        masterCategoryID,
        siteId,
        assortmentId,
        servicing,
        servicing: { itemServiceTypeID },
        servicing: { style },
        servicing: { text },
        servicing: { serviceQuantity }
    } = item;

以下内容可以是未定义的 -

服务，服务:{ itemServiceTypeID }，服务:{ style }，服务:{ text }，服务:{ serviceQuantity }

当分配给 const 时，如何检查上面的 undefined ？我想检查“服务”是否未定义，然后应省略其余的服务。

在没有 servicing 的项目中，控制台中出现 y.servicing is undefined。

Answer 1

试试这个:

let item = {
  masterCategoryID: '<masterCategoryID>',
  assortmentId: '<assortmentId>',
  siteId: '<siteId>',
  someDefinedProp: {
    someDefinedPropChild: '<someDefinedPropChild>'
  }
}

const {
    masterCategoryID,
    siteId,
    assortmentId,

    someDefinedProp,
    someDefinedProp: { someDefinedPropChild } = {},
    someDefinedProp: { someUndefinedPropChild } = {},

    servicing,
    servicing: { itemServiceTypeID } = {},
    servicing: { style } = {},
    servicing: { text } = {},
    servicing: { serviceQuantity } = {}
} = item;

console.log('someDefinedProp:', someDefinedProp)
console.log('someDefinedPropChild:', someDefinedPropChild)
console.log('someUndefinedPropChild:', someUndefinedPropChild)

console.log('servicing:', servicing)
console.log('itemServiceTypeID:', itemServiceTypeID)
console.log('style:', style)
console.log('text:', text)
console.log('serviceQuantity:', serviceQuantity)