Vue JS lodash findKey嵌套对象使用点表示法返回未定义

Question

我正试图从我拥有的某个资格数组中提取嵌套对象键的值，但由于某种原因，我得到了一个未定义的值，需要知道我缺少了什么。

给定以下数组：

const eligibilityCriteria = [
{ field: 'loan.amount', operator: '>=', value: 1000 },
{ field: 'loan.term', operator: '>=', value: 1 },
{ field: 'applicant.birthday', operator: '>=', value: 40 },
{ field: 'applicant.isHomeowner', operator: '==', value: false }
]

我需要从嵌套对象中找到loan.amount，并提取它的值：

我的大嵌套对象是(来自商店(

application: {
meta: {
brand: '',
version: '',
affiliate: '',
affiliate_full: '',
campaign: '',
client_hostname: '',
client_href: '',
client_origin: '',
client_useragent: '',
client_ip: '127.0.0.1',
icicle_hash: ''
},
loan: {
amount: 500,
term: null,
purpose: null
}
}

我现在的功能是：

checkEligibility () {
const eligibilityCriteria = [
{ field: 'loan.amount', operator: '>=', value: 1000 },
{ field: 'loan.term', operator: '>=', value: 1 },
{ field: 'applicant.birthday', operator: '>=', value: 40 },
{ field: 'applicant.isHomeowner', operator: '==', value: false }
]
for (const [index, offer] of this.datasets.offers.entries()) {
const eligibility = eligibilityCriteria
if (eligibility) {
for (const [ci, criteria] of eligibility.entries()) {
// TODO: this fails to pull the value, returns undefined
const field = _.findKey(this.$store.state.application.application, criteria.field)
}
}
}
}

我错过了什么？

Answer 1

您一定误解了_.findKey()对的作用

这个方法类似于_.find，只是它返回第一个元素的键谓词返回truthy-for而不是元素本身。

请参阅下面代码中的示例2。

如果你想从给定路径的对象中检索值，你必须使用_.property(((下面的例子2(

const eligibilityCriteria = [
{ field: 'loan.amount', operator: '>=', value: 1000 },
{ field: 'loan.term', operator: '>=', value: 1 },
]
const application = {
loan: {
amount: 500,
term: 2,
amount2: 0,
}
}
// example 1
// outputs "loan"
console.log(_.findKey(application, "amount"))     
// outputs undefined - there is no key in application object that has property chain "loan.amount"
console.log(_.findKey(application, "loan.amount"))
//  outputs undefined - "amount2" key is there but the value is falsy
console.log(_.findKey(application, "amount2"))     
// example 2
for (const [ci, criteria] of eligibilityCriteria.entries()) {
console.log(criteria.field, _.property(criteria.field)(application))
}

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