If I have some Strings like this :
"2018013108","2018013107","2018020100","2018013119","2018013114"....
the last 2 elements of each String represent hours.I want to get such a function: he can make the time one hour earlier and input.For example:
"2018013108" will change to "2018013107","2018020100" will change to "2018013123"...
This one hour shift takes place only within a year, so one hour ahead of time only requires attention to the conversion of months and dates.How should I code? Thx!!!
-1 if current hours is not 00 else your earlier hours will be 23 and then the days would be a day before or the last day of earlier month based on which day is today.
you can maintain a map of "month to end of days" to get the last day of previous month
Here's how it would look like;
import org.scalatest.FunSpec
class SubstractDateSpec extends FunSpec {
val monthDays = Map(
1 -> 31,
2 -> 28,
3 -> 31,
4 -> 30,
5 -> 31,
6 -> 30,
7 -> 31,
8 -> 31,
9 -> 30,
10 -> 31,
11 -> 31,
12 -> 31
)
def formatIt(data: Int): String = {
if (data < 10) "0" + data
else data + ""
}
def format(date: String): String = {
val year = date.slice(0, 4)
val month = date.slice(4, 6)
val days = date.slice(6, 8)
val hours = date.takeRight(2).toInt
if (hours == 0 && days.toInt == 1) {
val newMonth = month.toInt - 1
val newDay = monthDays(newMonth)
year + formatIt(newMonth) + formatIt(newDay) + "23"
} else if (hours == 0) {
year + month + formatIt(days.toInt - 1) + "23"
} else {
year + month + days + formatIt(hours - 1)
}
}
it("date") {
assert(format("2018013108") == "2018013107")
assert(format("2018101000") == "2018100923")
assert(format("2018020100") == "2018013123")
}
}