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
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
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);
};
这类函数有问题,我用parseInt()解决
Date.prototype.addDays = function(dias) {
var date = new Date(this.valueOf());
date.setDate(parseInt(date.getDate()) + parseInt(dias));
return date;
}
Date.prototype.addMonths = function(months) {
var date = new Date(this.valueOf());
date.setMonth(parseInt(date.getMonth()) + parseInt(months));
return date;
}
Date.prototype.addYears = function(years) {
var date = new Date(this.valueOf());
date.setFullYear(parseInt(date.getFullYear()) + parseInt(years));
return date;
}
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;
}
最简单的答案是,假设需要在当前日期上增加1天:
var currentDate = new Date();
var numberOfDayToAdd = 1;
currentDate.setDate(currentDate.getDate() + numberOfDayToAdd );
要逐行向您解释此代码的作用:
创建名为currentDate的当前日期变量。默认情况下,“new Date()”会自动将当前日期分配给变量。创建一个变量以保存要添加到日期的天数(您可以跳过此变量,直接使用第三行中的值)通过给定相同的值+所需的数字来更改Date的值(因为Date是保存在对象中的月份的日期)。切换到下个月将是自动的
您可以使用以下选项创建一个:-
Date.prototype.addDays=函数(天){var date=新日期(this.valueOf());date.setDate(date.getDate()+天);返回日期;}var date=新日期();console.log(date.addDays(5));
这会在必要时自动增加月份。例如:
8/31+1天将变为9/1。
直接使用setDate的问题是它是一个赋值函数,最好避免这种情况。ECMA认为将Date视为一个可变的类而不是一个不可变的结构是合适的。