我试图了解如何使用默认参数来解构虚假值和空值。以下是我运行过的一些示例:
// #1
const person = { email: '[email protected] /cdn-cgi/l/email-protection' }
const { email = '' } = person
// email is '[email protected] /cdn-cgi/l/email-protection'
// #2
const person = { email: '' }
const { email = '' } = person
// email is ''
// #3
const person = { email: false }
const { email = '' } = person
// email is boolean false. why?!
// #4
const person = { email: null }
const { email = '' } = person
// email is null. why?!
我是否可以编写一个快捷方式来解构 #3 和 #4 的假值和空值,以便我的电子邮件是一个空字符串?
Only undefined
将导致默认初始化程序在解构和函数参数目标中运行。如果您想将所有错误值恢复为默认值,请使用旧的||操作员 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR反而:
const email = person.email || '';
或者定位一个可变变量并使用逻辑或赋值 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_OR_assignment然后:
let { email } = person;
email ||= '';
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