javascript - 为数字添加符号

Question

我需要根据变量（借方/贷方）确定该值是增加还是减少，并返回一个有符号的数字。

由于这是该程序的关键部分，我只想仔细检查这是否确实是正确/最佳的方法：

var direction = 'debit';
var amount = 99.99
var signed = Number((direction === 'debit' ? '-' : '') + Math.abs(amount))
console.log(signed) // -99.99

var direction = 'credit';
var amount = 99.99
var signed = Number((direction === 'debit' ? '-' : '') + Math.abs(amount))
console.log(signed) // 99.99

Answer 1

对于始终为正数，您可以乘以想要的符号。

var direction = 'debit';
var amount = 99.99
var signed = (direction === 'debit' ? -1 : 1) * amount
console.log(signed) // -99.99

direction = 'credit';
amount = 99.99
signed = (direction === 'debit' ? -1 : 1) * amount
console.log(signed) // 99.99