如何在JavaScript中计算昨天作为日期?
当前回答
这里有2个一句话:
new Date(new Date().setHours(-1))
new Date(Date.now() - 86400000)
其他回答
这将产生昨天零点的分钟精确
var d = new Date();
d.setDate(d.getDate() - 1);
d.setTime(d.getTime()-d.getHours()*3600*1000-d.getMinutes()*60*1000);
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);
令人惊讶的是,没有答案指向最简单的跨浏览器解决方案
找到昨天的同一时间*:
var yesterday = new Date(Date.now() - 86400000); // that is: 24 * 60 * 60 * 1000
*:如果您的用例不介意日历的不精确(如夏令时),那么这个方法很有效,否则我建议使用https://moment.github.io/luxon/
[2022年4月]:下面是一个扩展Date原型的代码片段(不污染全局命名空间)
[edit sept 2020]:一个包含之前答案的片段,并添加了一个箭头函数。
// a (not very efficient) oneliner let yesterday = new Date(new Date().setDate(new Date().getDate()-1)); console.log(`Yesterday (oneliner)\n${yesterday}`); // a function call yesterday = ( function(){this.setDate(this.getDate()-1); return this} ) .call(new Date); console.log(`Yesterday (function call)\n${yesterday}`); // an iife (immediately invoked function expression) yesterday = function(d){ d.setDate(d.getDate()-1); return d}(new Date); console.log(`Yesterday (iife)\n${yesterday}`); // oneliner using es6 arrow function yesterday = ( d => new Date(d.setDate(d.getDate()-1)) )(new Date); console.log(`Yesterday (es6 arrow iife)\n${yesterday}`); // use a method const getYesterday = (dateOnly = false) => { let d = new Date(); d.setDate(d.getDate() - 1); return dateOnly ? new Date(d).toDateString() : d; }; console.log(`Yesterday (method)\n${getYesterday()}`); console.log(`Yesterday (method dateOnly=true)\n${getYesterday(true)}`); // use Date.now console.log(`Yesterday, using Date.now\n${new Date(Date.now() - 864e5)}`); .as-console-wrapper { max-height: 100% !important; }
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)