Function add/addMonths compute error

[ikarosu]

new Date().addMonths(0)
Fri May 31 2019 17:07:50 GMT+0800 (China Standard Time)
new Date().addMonths(1)
Mon Jul 01 2019 17:07:58 GMT+0800 (China Standard Time)
new Date().addMonths(2)
Wed Jul 31 2019 17:08:01 GMT+0800 (China Standard Time)
new Date().addMonths(3)
Sat Aug 31 2019 17:08:03 GMT+0800 (China Standard Time)
new Date().add({ months: 0 })
Fri May 31 2019 17:08:24 GMT+0800 (China Standard Time)
new Date().add({ months: 1 })
Mon Jul 01 2019 17:08:27 GMT+0800 (China Standard Time)
new Date().add({ months: 2 })
Wed Jul 31 2019 17:08:29 GMT+0800 (China Standard Time)
new Date().add({ months: 3 })
Sat Aug 31 2019 17:08:32 GMT+0800 (China Standard Time)

[ikarosu]

When the date is 31,and calling the setMonths() method.If there are no 31 days this months,then will get the 1st of the next month.

[JerrySievert]

add and addMonths use Date.setMonth:

new Date(new Date().setMonth(5))

[ikarosu]

Yeah,I know.But we can avoid this problem like this:

const d = new Date()
d.setDate(1)
new Date(d.clone().setMonth(d.getMonth() + i))