swift 类型转换

1.获取当前时间

var curDate = NSDate()

var dateFormatter = NSDateFormatter()

var timeFormatter = NSDateFormatter()

dateFormatter.dateFormat = “yyy-MM-dd”

timeFormatter.dateFormat = “HH:mm:ss SSS”

var dateStr = dateFormatter.stringFromDate(curDate)

var timeStr = timeFormatter.stringFromDate(curDate)

2.时间转换

func dateFromString(dateStr: String) -> NSDate? {

let dateFormatter = NSDateFormatter()

dateFormatter.dateFormat = “yyyy-MM-dd”

let date = dateFormatter.dateFromString(dateStr)

return date

}

func stringFromDate(format: String, date: NSDate) -> String {

let locale = NSLocale.currentLocale()

let dateFormat = NSDateFormatter.dateFormatFromTemplate(format, options: 0, locale: locale)

let dateformatter = NSDateFormatter()

dateformatter.dateFormat = dateFormat

return dateformatter.stringFromDate(date)

}

3.String转换为Double

NSNumberFormatter().numberFromString(display.text!)!.doubleValue

或者

(display.text! as NSString).doubleValue

4.Double转换为String，小数为0时不显示后面的.0

let intValue = Int(newValue)

if (Double(intValue) == newValue) {

display.text = “(intValue)”

} else {

display.text = “(newValue)”

}