Sorting an array containing strings and integers by multiple properties

Question

I have an array of SortedELRStructure that I need to sort by it's elr property, AS WELL AS by it's railwayID. The trouble I am having is the railwayID is populated using a string value, as it could be anything like ["1A", "C0284", "300000"] etc so when I sort the array by railwayID is sorts them as strings and I get back ["101023", "10A", "11", "12", "110032"] (example).

How do I sort an array of this type by the numerical value of railwayID, even when it contains letters, in addition to sorting by the elr string?

I've tried the following so far, which I think getting close but the railway ID is still being sorted as a string:

let sorted = sortedDayListItems.sorted { t1, t2 in
    if t1.elr == t2.elr {
        if t1.railwayID.isInt && t2.railwayID.isInt {
            return Int(t1.railwayID)! < Int(t2.railwayID)!
        } else {
                 
        }
        return t1.railwayID < t2.railwayID
    }
    return (t1.elr != nil) && (t2.elr == nil)
}

struct SortedELRStructure {
    var dataItem: CalendarSurveyDataItem
    var elr: String
    var railwayID: String
}

I did already see that post. They don't specify how to use that to sort by multiple properties, and I can't work that part out. — jbeu425
– jbeu425, Commented Nov 3, 2020 at 22:44
It's not related to "sort by multiple properties", in the end, it's how to compare ralwayID when their elr are the same, and it's exactly the linked question (with multiple answers to adapt maybe to your case, because it's unclear in where "C0284" would go against "B01", before or after it?) — Larme
– Larme, Commented Nov 3, 2020 at 22:45
So what is the expected result ["10A", "11", "12", "101023", "110032"] ? — Leo Dabus
– Leo Dabus, Commented Nov 3, 2020 at 22:47

Leo Dabus · Accepted Answer · 2020-11-03 22:54:30Z

1

You just need to create a custom sort method. If ELR elements are equal sort the ralwayID using localized standard compare otherwise just sort by ELR

let sorted = sortedDayListItems.sorted {
    if $0.elr == $1.elr {
        return $0.railwayID.localizedStandardCompare($1.railwayID) == .orderedAscending
    }
    return $0.elr < $1.elr
}

answered Nov 3, 2020 at 22:54

Leo Dabus

237k61 gold badges512 silver badges624 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Sorting an array containing strings and integers by multiple properties

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related