swift - 从字符串 swift 计算年龄
问题描述
我正在尝试计算从婴儿到成人(例如 8 周大、4 个月大或 22 岁)的任何人的年龄。但是我的计算失败了,我找不到在哪里。如果我在 2020 年 10 月 16 日输入 DOB,它会返回 8 周大,这是正确的。但是,如果我输入 2020 年 10 月 26 日,它会返回 11 周,这是不正确的。任何帮助深表感谢。
年龄功能:
let bornOn = "10/16/2020"
func calculateAge(dob: String, format: String = "MM/dd/yyyy") -> String{
let df = DateFormatter()
df.dateFormat = format
let date = df.date(from: dob)
guard let val = date else{
return ""
}
var years = 0
var months = 0
var days = 0
let cal = Calendar.current
years = cal.component(.year, from: Date()) - cal.component(.year, from: val)
let currentMonth = cal.component(.month, from: Date())
let birthMonth = cal.component(.month, from: val)
months = currentMonth - birthMonth
if months < 0 {
years = years - 1
months = 12 - birthMonth
if cal.component(.day, from: Date()) < cal.component(.day, from: val){
months = months - 1
}
}else if months == 0 && cal.component(.day, from: Date()) < cal.component(.day, from: val){
years = years - 1
months = 11
}
if cal.component(.day, from: Date()) > cal.component(.day, from: val){
days = cal.component(.day, from: Date()) - cal.component(.day, from: val)
}else if cal.component(.day, from: Date()) < cal.component(.day, from: val){
let today = cal.component(.day, from: Date())
let date = cal.date(byAdding: .month, value: -1, to: Date())
days = date!.daysInMonth - cal.component(.day, from: val) + today
}else{
days = 0
if months == 12 {
years = years + 1
months = 0
}
}
print("Years: \(years), Months: \(months), Days: \(days)")
if years > 0{
if years == 1{
return "\(years) year old"
}else{
return "\(years) years old"
}
}else if months > 4{
return "\(months) months old"
}else {
if months >= 1{
let daysleftInMonth = months * 30
print(daysleftInMonth)
days += daysleftInMonth
}
let weeks = days / 7
return "\(weeks) weeks old"
}
}
extension Date{
var daysInMonth:Int{
let calendar = Calendar.current
let dateComponents = DateComponents(year: calendar.component(.year, from: self), month: calendar.component(.month, from: self))
let date = calendar.date(from: dateComponents)!
let range = calendar.range(of: .day, in: .month, for: date)!
let numDays = range.count
return numDays
}
}
calculateAge(dob: bornOn)
解决方案
你走错了方向。您需要解析日期字符串并将其转换为日期并使用 DateComponentsFormatter 显示此人的年龄。您还可以获取从生日到今天的日期组件:
extension Formatter {
static let dateMMddyyyy: DateFormatter = {
let formatter = DateFormatter()
formatter.locale = .init(identifier: "en_US_POSIX")
formatter.dateFormat = "MM/dd/yyyy"
return formatter
}()
static let dateComponents: DateComponentsFormatter = {
let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.day, .month, .year]
formatter.maximumUnitCount = 1
return formatter
}()
}
extension Date {
var ageComponents: DateComponents { Calendar.current.dateComponents([.year, .month, .day], from: self, to: Date()) }
var relativeAge: String {
Formatter.dateComponents.allowedUnits = ageComponents.month! >= 2 ?
[.day, .month, .year] : [.weekOfMonth]
return Formatter.dateComponents.string(from: self, to: Date())!
}
}
extension String {
var dateFromMMddyyyy: Date? { Formatter.dateMMddyyyy.date(from: self) }
}
"09/10/1970".dateFromMMddyyyy?.relativeAge // "50 years"
"10/16/2020".dateFromMMddyyyy?.relativeAge // "2 months"
"10/23/2020".dateFromMMddyyyy?.relativeAge // "7 weeks"
推荐阅读
- angular - 删除动态行中选定的下拉值
- javascript - AngularJs 无法从函数返回数据
- javascript - 监听firestore中Root集合云功能的变化
- linux - 在 Ubuntu 18 中使用 Ubuntu 16 的共享库
- angular - Jasmine:测试嵌套函数是否被调用
- ms-access - 通过子表单从表中删除记录的 VBA 代码
- applescript - Applescript:单击特定的菜单栏项
- r - 显示没有任何 tab_stat_*() 的表
- node.js - 在Node js上使用sqlite3在多列上插入多行
- appcelerator - 工作室打不开