用Swift写输入日期计算天数的Demo

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//输入XX年XX月XX日,计算出日期

// Playground - noun: a place where people can play
 import UIKit

func days (year: Int, month : Int, day : Int) ->(Int) {
if (year < 0 || month < 0 || month > 12 || day < 0 || day > 31) {
println("输入错误")
return 0
}
var sum = 0
var add = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]
switch month {
case 1 :
sum = day + add[month - 1]
case 2 :
sum = day + add[month - 1]
case 3 :
sum = day + add[month - 1]
case 4 :
sum = day + add[month - 1]
case 5 :
sum = day + add[month - 1]
case 6 :
sum = day + add[month - 1]
case 7 :
sum = day + add[month - 1]
case 8 :
sum = day + add[month - 1]
case 9 :
sum = day + add[month - 1]
case 10 :
sum = day + add[month - 1]
case 11 :
sum = day + add[month - 1]
case 12 :
sum = day + add[month - 1]
default :
println("输入错误")
}
if (year % 4 == 0 || (year % 400 == 0 && year % 100 != 0)) && (month > 2) {
println("闰年")
sum += 1
}
return sum;
}
days(1501, 3, 1)

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