react，js代码里的传值问题？

部分代码如下：

import calendar from 'js-calendar-converter'
const News = () => {
  const [selectedDate, setSelectedDate] = useState(null)
  let tgdz = ''
  let v
  const formatDate = (date) => {
    const year = date.getFullYear()
    const month = date.getMonth() + 1
    const day = date.getDate()
    const hour = date.getHours()
    const minute = date.getMinutes()
    const lunarDate = calendar.solar2lunar(year, month, day)
    v = lunarDate.gzDay[0]

    tgdz = `${lunarDate.gzYear}年 ${lunarDate.gzMonth}月 ${lunarDate.gzDay}日`
    return `${year}年${month}月${day}日 ${hour}时${minute}分`
  }
console.log(v)
return (
    <div>{selectedDate ? formatDate(selectedDate) : ''}</div>
)
}

v的打印结果是undifined
以上代码里，为何lunarDate里的值得传不出去变量v里？如何修改？请在现有代码基础上展示说明，谢谢

v 在函数里赋值，函数没运行

你起码在打印之前调用一下你的formatDate函数吧