嵌套对象解构 [英] Nested Object destructuring

问题描述

在销毁对象时，有时会遇到这样的问题:不知道键是否存在，然后尝试从它们中获取值.这显然是错误的，因为它们是未定义的.例如:

When destructuring objects, I sometimes run into the issue of not knowing whether or not keys exist, and then trying to pull values from them. This obviously errors, since they are undefined. For example:

期待这样的事情:

{ user: { name: { first: 'Trey', last: 'Hakanson' } } }

但是我实际上得到了:

{ user: {} }

并尝试破坏此类错误:

const { user: { name: { first: firstName, last: lastName } } } = data

在解构之前，有什么方法可以分配默认值吗?例如如果name键不存在则分配name = { first: 'Hello', last: 'World' }?

is there any way to assign a default value earlier in the deconstruction? Such as assigning name = { first: 'Hello', last: 'World' } if the name key doesn't exist?

推荐答案

const { user: { name: { first: firstName = 'firstName', last: lastName = 'lastName' } = {} } = {} } = data

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