如何格式化 JavaScript 日期 [英] How to format a JavaScript date

问题描述

在 JavaScript 中，如何将日期对象格式化为 10-Aug-2010?

In JavaScript, how can I format a date object to print as 10-Aug-2010?

推荐答案

对于自定义分隔的日期格式，你必须把日期(或时间)拉出来DateTimeFormat 对象(它是的一部分ECMAScript Internationalization API)，然后手动创建一个字符串使用您想要的分隔符.

For custom-delimited date formats, you have to pull out the date (or time) components from a DateTimeFormat object (which is part of the ECMAScript Internationalization API), and then manually create a string with the delimiters you want.

为此，您可以使用 DateTimeFormat#formatToParts.你可以解构数组，但这并不理想，因为数组输出取决于语言环境:

To do this, you can use DateTimeFormat#formatToParts. You could destructure the array, but that is not ideal, as the array output depends on the locale:

{ // example 1
   let f = new Intl.DateTimeFormat('en');
   let a = f.formatToParts();
   console.log(a);
}
{ // example 2
   let f = new Intl.DateTimeFormat('hi');
   let a = f.formatToParts();
   console.log(a);
}

最好将格式数组映射到结果字符串:

Better would be to map a format array to resultant strings:

function join(t, a, s) {
   function format(m) {
      let f = new Intl.DateTimeFormat('en', m);
      return f.format(t);
   }
   return a.map(format).join(s);
}

let a = [{day: 'numeric'}, {month: 'short'}, {year: 'numeric'}];
let s = join(new Date, a, '-');
console.log(s);

您还可以使用以下方法一一提取 DateTimeFormat 的部分DateTimeFormat#format，但请注意使用此方法时，截至 3 月2020 年，ECMAScript 实现中存在一个错误.分钟和秒的前导零(这个错误被方法规避了以上).

You can also pull out the parts of a DateTimeFormat one-by-one using DateTimeFormat#format, but note that when using this method, as of March 2020, there is a bug in the ECMAScript implementation when it comes to leading zeros on minutes and seconds (this bug is circumvented by the approach above).

let d = new Date(2010, 7, 5);
let ye = new Intl.DateTimeFormat('en', { year: 'numeric' }).format(d);
let mo = new Intl.DateTimeFormat('en', { month: 'short' }).format(d);
let da = new Intl.DateTimeFormat('en', { day: '2-digit' }).format(d);
console.log(`${da}-${mo}-${ye}`);

处理日期和时间时，通常值得使用库(例如.moment.js、luxon) 因为许多隐藏的复杂性领域.

When working with dates and times, it is usually worth using a library (eg. moment.js, luxon) because of the many hidden complexities of the field.

请注意，上述解决方案中使用的 ECMAScript 国际化 API在 IE10 中不支持 (0.03% 2 月份全球浏览器市场份额2020).

Note that the ECMAScript Internationalization API, used in the solutions above is not supported in IE10 (0.03% global browser market share in Feb 2020).

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