如何使用JavaScript将日期添加到当前日期?JavaScript是否有像.NET的AddDay()那样的内置函数?
当前回答
我知道,但有时我喜欢这样:
function addDays(days) {
return new Date(Date.now() + 864e5 * days);
}
其他回答
同样的答案是:如何将天数添加到今天的日期?
function DaysOfMonth(nYear, nMonth) {
switch (nMonth) {
case 0: // January
return 31; break;
case 1: // February
if ((nYear % 4) == 0) {
return 29;
}
else {
return 28;
};
break;
case 2: // March
return 31; break;
case 3: // April
return 30; break;
case 4: // May
return 31; break;
case 5: // June
return 30; break;
case 6: // July
return 31; break;
case 7: // August
return 31; break;
case 8: // September
return 30; break;
case 9: // October
return 31; break;
case 10: // November
return 30; break;
case 11: // December
return 31; break;
}
};
function SkipDate(dDate, skipDays) {
var nYear = dDate.getFullYear();
var nMonth = dDate.getMonth();
var nDate = dDate.getDate();
var remainDays = skipDays;
var dRunDate = dDate;
while (remainDays > 0) {
remainDays_month = DaysOfMonth(nYear, nMonth) - nDate;
if (remainDays > remainDays_month) {
remainDays = remainDays - remainDays_month - 1;
nDate = 1;
if (nMonth < 11) { nMonth = nMonth + 1; }
else {
nMonth = 0;
nYear = nYear + 1;
};
}
else {
nDate = nDate + remainDays;
remainDays = 0;
};
dRunDate = Date(nYear, nMonth, nDate);
}
return new Date(nYear, nMonth, nDate);
};
date d = new Date() // current date
date tomorrow = d.setMonth(d.getMonth(),d.getDate()+1) // return a date incremented by 0 months and 1 day
我对所提出的解决方案的夏令时有问题。
通过改用getUTCDate/setUTCDate,我解决了问题。
// Curried, so that I can create helper functions like `add1Day`
const addDays = num => date => {
// Make a working copy so we don't mutate the supplied date.
const d = new Date(date);
d.setUTCDate(d.getUTCDate() + num);
return d;
}
这些答案让我感到困惑,我更喜欢:
var ms = new Date().getTime() + 86400000;
var tomorrow = new Date(ms);
getTime()给出了自1970年以来的毫秒数,86400000是一天中的毫秒数。因此,ms包含所需日期的毫秒。
使用毫秒构造函数可以得到所需的日期对象。
我昨晚创建了这些扩展:可以传递正值或负值;
例子:
var someDate = new Date();
var expirationDate = someDate.addDays(10);
var previous = someDate.addDays(-5);
Date.prototype.addDays = function (num) {
var value = this.valueOf();
value += 86400000 * num;
return new Date(value);
}
Date.prototype.addSeconds = function (num) {
var value = this.valueOf();
value += 1000 * num;
return new Date(value);
}
Date.prototype.addMinutes = function (num) {
var value = this.valueOf();
value += 60000 * num;
return new Date(value);
}
Date.prototype.addHours = function (num) {
var value = this.valueOf();
value += 3600000 * num;
return new Date(value);
}
Date.prototype.addMonths = function (num) {
var value = new Date(this.valueOf());
var mo = this.getMonth();
var yr = this.getYear();
mo = (mo + num) % 12;
if (0 > mo) {
yr += (this.getMonth() + num - mo - 12) / 12;
mo += 12;
}
else
yr += ((this.getMonth() + num - mo) / 12);
value.setMonth(mo);
value.setYear(yr);
return value;
}