javascript - 如何在 javaScript (Node.Js) 中将私有(private)变量导出到公共(public)变量

Question

比如我有这样一个计算程序:

function cal(salary, additionalSalary) {
  var salary;
  var additionalSalary;
  var totalPay = salary + additionalSalary;
}

function 401k() {
  var specialAccount = totalPay * 0.37;
  var normalAccount = totalPay - specialAccount;
}

我的问题是如何从函数中导出 totalPay 变量，使其成为在 401k 函数中使用的公共(public)变量。谢谢。

Answer 1

您可以使用 closures和 immediately invoked function在薪水计算中处理 let totalPay 变量的表达式:

代码:

const Salary = (() => {
  let totalPay
  const cal = (salary, additionalSalary) => {
    totalPay = salary + additionalSalary
  }
  const k401 = () => {
    const specialAccount = totalPay * 0.37
    const normalAccount = totalPay - specialAccount
    return normalAccount
  }
  return {
    cal: cal,
    k401: k401
  }
})()

// Use it like this
Salary.cal(5000, 250)
const k401 = Salary.k401()

console.log('k401:', k401)