Date.prototype.setDate()

¥Syntax

setDate(dateValue)

¥Parameters

dateValue

代表月份中的某天的整数。

¥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.

¥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.

¥Examples

¥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)

¥See also

• Date()
• Date.prototype.getDate()
• Date.prototype.setUTCDate()