如果你既想获取昨天的日期，又想将日期格式化为人类可读的格式，可以考虑创建一个自定义DateHelper对象，看起来像这样:

var DateHelper = { addDays : function(aDate, numberOfDays) { aDate.setDate(aDate.getDate() + numberOfDays); // Add numberOfDays return aDate; // Return the date }, format : function format(date) { return [ ("0" + date.getDate()).slice(-2), // Get day and pad it with zeroes ("0" + (date.getMonth()+1)).slice(-2), // Get month and pad it with zeroes date.getFullYear() // Get full year ].join('/'); // Glue the pieces together } } // With this helper, you can now just use one line of readable code to : // --------------------------------------------------------------------- // 1. Get the current date // 2. Subtract 1 day // 3. Format it // 4. Output it // --------------------------------------------------------------------- document.body.innerHTML = DateHelper.format(DateHelper.addDays(new Date(), -1));

(也可以参看这把小提琴)

如果你既想获取昨天的日期，又想将日期格式化为人类可读的格式，可以考虑创建一个自定义DateHelper对象，看起来像这样:

var DateHelper = { addDays : function(aDate, numberOfDays) { aDate.setDate(aDate.getDate() + numberOfDays); // Add numberOfDays return aDate; // Return the date }, format : function format(date) { return [ ("0" + date.getDate()).slice(-2), // Get day and pad it with zeroes ("0" + (date.getMonth()+1)).slice(-2), // Get month and pad it with zeroes date.getFullYear() // Get full year ].join('/'); // Glue the pieces together } } // With this helper, you can now just use one line of readable code to : // --------------------------------------------------------------------- // 1. Get the current date // 2. Subtract 1 day // 3. Format it // 4. Output it // --------------------------------------------------------------------- document.body.innerHTML = DateHelper.format(DateHelper.addDays(new Date(), -1));

(也可以参看这把小提琴)

//Create a date object using the current time
var now = new Date();

//Subtract one day from it
now.setDate(now.getDate()-1);

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。

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);

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)