我想要这样的答案:

const yesterday = d => new Date(d.setDate(d.getDate() - 1));

问题是它突变了d，所以让我们把突变藏在里面。

const yesterday = (date) => {
  const dateCopy = new Date(date);
  return new Date(dateCopy.setDate(dateCopy.getDate() - 1));
}

我们可以将其分解为一行表达式，但它变得有点难以阅读:

const yesterday = d => new Date(new Date(d).setDate(d.getDate() - 1));

我将其扩展为addDays和addMonths函数:

/** * Add (or subtract) days from a date * * @param {Number} days * @returns {Function} Date => Date + days */ const addDays = (days) => (date) => new Date(new Date(date).setDate(date.getDate() + days)); /** * Add (or subtract) months from a date * * @param {Number} months * @returns {Function} Date => Date + months */ const addMonths = (months) => (date) => new Date(new Date(date).setMonth(date.getMonth() + months)); // We can recreate the yesterday function: const yesterday = addDays(-1) // note that `now` doesn't get mutated const now = new Date(); console.log({ now, yesterday: yesterday(now) }) const lastMonth = addMonths(-1)(now); console.log({ now, lastMonth }) .as-console-wrapper { max-height: 100% !important; }

但在这一点上，你可能想开始使用date-fns addDays。

var today = new Date(); var yesterday1 =新日期(新日期()。setDate(new Date().getDate() - 1)); var yesterday2 =新的日期(Date.now() - 86400000); var yesterday3 = new Date(Date.now() - 1000*60*60*24); var yesterday4 = new Date((new Date()).valueOf() - 1000*60*60*24); 今天console.log(“:“今天+); 昨天console.log(“:”+ yesterday1); 昨天console.log(“:”+ yesterday2); 昨天console.log(“:”+ yesterday3); 昨天console.log(“:”+ yesterday4);

"Date.now() - 86400000"在夏令时结束日(当天有25小时)不起作用

另一个选择是使用Closure:

var d = new goog.date.Date();
d.add(new goog.date.Interval(0, 0, -1));

为了概括问题并使用其他差异计算:

var yesterday = new Date((new Date()).valueOf() - 1000*60*60*24);

这将创建一个基于“now”值的新date对象，该值为整数，表示Unix epoch(单位为毫秒减去一天)。

两天前:

var twoDaysAgo = new Date((new Date()).valueOf() - 1000*60*60*24*2);

一小时前:

var oneHourAgo = new Date((new Date()).valueOf() - 1000*60*60);

我想要这样的答案:

const yesterday = d => new Date(d.setDate(d.getDate() - 1));

问题是它突变了d，所以让我们把突变藏在里面。

const yesterday = (date) => {
  const dateCopy = new Date(date);
  return new Date(dateCopy.setDate(dateCopy.getDate() - 1));
}

我们可以将其分解为一行表达式，但它变得有点难以阅读:

const yesterday = d => new Date(new Date(d).setDate(d.getDate() - 1));

我将其扩展为addDays和addMonths函数:

/** * Add (or subtract) days from a date * * @param {Number} days * @returns {Function} Date => Date + days */ const addDays = (days) => (date) => new Date(new Date(date).setDate(date.getDate() + days)); /** * Add (or subtract) months from a date * * @param {Number} months * @returns {Function} Date => Date + months */ const addMonths = (months) => (date) => new Date(new Date(date).setMonth(date.getMonth() + months)); // We can recreate the yesterday function: const yesterday = addDays(-1) // note that `now` doesn't get mutated const now = new Date(); console.log({ now, yesterday: yesterday(now) }) const lastMonth = addMonths(-1)(now); console.log({ now, lastMonth }) .as-console-wrapper { max-height: 100% !important; }

但在这一点上，你可能想开始使用date-fns addDays。

排在第二的法比亚诺和其他一些人已经给出了类似的答案，但这样做会让事情看起来更明显。

86400000 =一天中的毫秒

const event = new Date(); console.log(new Date(Date.parse(event) - 86400000)) console.log(事件)