如何用Momentjs精确计算年龄？

Question

我想根据一个人的出生日期计算他的年龄。

我知道可以通过

moment().diff(date_of_birth, 'months')

返回出生后的月数或年数。

我想返回更具体的东西，像这样：

23 days

（如果此人不到一个月大）或

2 months

或

1 year 2 months

我们可以用 Momentjs 做到这一点吗？

Answer 1

试试这个

let duration = moment.duration(moment().diff('1987-11-15'));
const formatDuration = (duration) => {
    let years = duration.years();
    let months= duration.months();
    let days= duration.days();
    let result = '';
    if (years === 1) {
        result += 'one year ';
    } else if (years > 1) {
        result += years + ' years ';
    }
    if (months === 1) {
        result += 'one month ';
    } else if (months > 1) {
        result += months + ' months ';
    }
    if (days === 1) {
        result += 'one day ';
    } else if (days > 1) {
        result += days + ' days ';
    }
    return result;
}

console.log('Your age is ', formatDuration(duration) );

// you may also try this.
duration.humanize();

Answer 2

使用

the third paramter=true

moment.diff

应该是一种选择。

正如moment diff所说：

默认情况下，moment#diff 会将结果截断为零小数 地方，返回一个整数。如果你想要一个浮点数， 将 true 作为第三个参数传递。 在 2.0.0 之前，moment#diff 返回了一个 数字四舍五入到最接近的整数，而不是截断的数字。

像下面的演示：

function displayAge(birth, target) {
  let months = target.diff(birth, 'months', true)
  let birthSpan = {year: Math.floor(months/12), month: Math.floor(months)%12, day: Math.round((months%1)*target.daysInMonth(),0)}
  // you can adjust below logic as your requirements by yourself
  if (birthSpan.year < 1 && birthSpan.month < 1) {
    return birthSpan.day + ' day' + (birthSpan.day > 1 ? 's' : '')
  } else if (birthSpan.year < 1) {
    return birthSpan.month + ' month' + (birthSpan.month > 1 ? 's ' : ' ') + birthSpan.day + ' day' + (birthSpan.day > 1 ? 's' : '')
  } else if (birthSpan.year < 2) {
    return birthSpan.year + ' year' + (birthSpan.year > 1 ? 's ' : ' ') + birthSpan.month + ' month' + (birthSpan.month > 1 ? 's ' : '')
  } else {
    return birthSpan.year + ' year' + (birthSpan.year > 1 ? 's' : '')
  }
  
}
let birth = moment([1997, 3, 7])
console.log(displayAge(birth, moment()))
console.log(displayAge(birth, moment([1997, 3, 8])))
console.log(displayAge(birth, moment([1997, 3, 10])))
console.log(displayAge(birth, moment([1997, 4, 8])))
console.log(displayAge(birth, moment([1998, 4, 8])))
console.log(displayAge(birth, moment([1998, 5, 8])))
console.log(displayAge(birth, moment([1999, 4, 8])))

<script src="https://momentjs.com/downloads/moment.js"></script>

Answer 3

Rainer plummer answer 的 TS 版本

   const duration = moment.duration(moment().diff('1987-11-15'));
    const formatDuration = (duration: moment.Duration) => {
        const years = duration.years();
        const months = duration.months();
        const days = duration.days();
        let result = '';
        if (years === 1) {
            result += 'one year ';
        } else if (years > 1) {
            result += years + ' years ';
        }
        if (months === 1) {
            result += 'one month ';
        } else if (months > 1) {
            result += months + ' months ';
        }
        if (days === 1) {
            result += 'one day ';
        } else if (days > 1) {
            result += days + ' days ';
        }
        return result;
    };

    console.log('Your age is ', formatDuration(duration));

    // you may also try this.
    duration.humanize();