Question

我试图从连续3000天构建一个数据数组，但代码只会从一个日期提取数据3000次。当我打印我不断增加的日期（theincreasingnumberofdays）时，我可以看到它每次循环都会在日期中添加一天，但是当我在循环后读出数组时它就是所有的相同的数据3000次。

class day
{
var week: Int?
var date: Int?
var month: Int?
var year: Int?
var weekday: Int?
}


@IBAction func pressbuttontodefinearray(sender: AnyObject) {
    print("button has been pressed")

    if (theArrayContainingAllTheUserData.count > 1) {
        print("array contains something allready and we don't do anything")
        return
    }

    print("array is empty and we're filling it right now")
    var ScoopDay =  day()

    var numberofloops = 0

    while theArrayContainingAllTheUserData.count < 3000
    {
        var theincreasingnumberofdays: NSDate {
            return NSCalendar.current.date(byAdding: .day, value: numberofloops, to: NSDate() as Date)! as NSDate
        }

        print(theincreasingnumberofdays)

        let myCalendar = NSCalendar(calendarIdentifier: NSCalendar.Identifier.gregorian)!

        // var thenextdate = calendar.date(byAdding: .day, value: numberofloops, to: date as Date)
        numberofloops=numberofloops+1
        ScoopDay.week=Int(myCalendar.component(.weekday, from: theincreasingnumberofdays as Date!))
        ScoopDay.date=Int(myCalendar.component(.day, from: theincreasingnumberofdays as Date!))
        ScoopDay.month=Int(myCalendar.component(.month, from: theincreasingnumberofdays as Date!))
        ScoopDay.year=Int(myCalendar.component(.year, from: theincreasingnumberofdays as Date!))
        ScoopDay.weekday=Int(myCalendar.component(.weekday, from: theincreasingnumberofdays as Date!))

        theArrayContainingAllTheUserData.append(ScoopDay)
    }

    print("we're done with this looping business. Let's print it")
    var placeinarray = 0
    while placeinarray < 2998
    {
        print("Here is", placeinarray, theArrayContainingAllTheUserData[placeinarray].date, theArrayContainingAllTheUserData[placeinarray].month)
        placeinarray=placeinarray+1
    }

    return
}

Answer 1

问题是有一个名为day的{{1}}对象，并且您将该对象添加到数组3000次。因此，数组最终会对该单个对象进行3000次引用，该对象包含您为其分配的最后一个值。

您可以通过移动线

来解决此问题

ScoopDay

循环内部。这样，您将创建3000个不同的var ScoopDay = day()个对象，每个对象具有不同的内容。

Swift样式提示：大写类名的第一个字母，并小写变量名的第一个字母，所以：

day

和

class Day

试图从多个连续日期获取数据

1 个答案: