Date.prototype.setDate()
Date
实例的 setDate()
方法根据当地时间更改此日期的月份日期。
¥The setDate()
method of Date
instances changes the day of the month for this date according to local time.
Try it
语法
参数
返回值
¥Return value
就地更改 Date
对象,并返回其新的 timestamp。如果 dateValue
是 NaN
(或获取 coerced 到 NaN
的其他值,例如 undefined
),则日期设置为 失效日期 并返回 NaN
。
¥Changes the Date
object in place, and returns its new timestamp. If dateValue
is NaN
(or other values that get coerced to NaN
, such as undefined
), the date is set to Invalid Date and NaN
is returned.
描述
¥Description
如果你指定的数字超出预期范围,则 Date
对象中的日期信息将相应更新。例如,如果 Date
对象为 6 月 1 日,则 dateValue
为 40 会将日期更改为 7 月 10 日,而 dateValue
为 0 将日期更改为上个月的最后一天,即 5 月 31 日。
¥If you specify a number outside the expected range, the date information in the Date
object is updated accordingly. For example, if the Date
object holds June 1st, a dateValue
of 40 changes the date to July 10th, while a dateValue
of 0 changes the date to the last day of the previous month, May 31st.
示例
使用 setDate()
¥Using setDate()
const theBigDay = new Date(1962, 6, 7, 12); // noon of 1962-07-07 (7th of July 1962, month is 0-indexed)
const theBigDay2 = new Date(theBigDay).setDate(24); // 1962-07-24 (24th of July 1962)
const theBigDay3 = new Date(theBigDay).setDate(32); // 1962-08-01 (1st of August 1962)
const theBigDay4 = new Date(theBigDay).setDate(22); // 1962-07-22 (22nd of July 1962)
const theBigDay5 = new Date(theBigDay).setDate(0); // 1962-06-30 (30th of June 1962)
const theBigDay6 = new Date(theBigDay).setDate(98); // 1962-10-06 (6th of October 1962)
const theBigDay7 = new Date(theBigDay).setDate(-50); // 1962-05-11 (11th of May 1962)
规范
Specification |
---|
ECMAScript Language Specification # sec-date.prototype.setdate |
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