Move some objects of array at the end in swift 3

Question

I have a list of conversation which needs to be sorted on last updated time. I am able to do this but now i also need to add a check that if user is not included in conversation then it should appear at the end of list.

func sortConversationList () {
self.conversationList = self.conversationList.sorted(by: { $0.lastupdatedTime! > $1.lastupdatedTime! })
    for (index, conversation) in self.conversationList.enumerated() {
        if (conversation.isIncluded == kNo) {
            self.conversationList.move(at: index, to: self.conversationList.endIndex-1)
        }
    }
    self.tableView.reloadData()
}
 mutating func move(at oldIndex: Int, to newIndex: Int) {
        self.insert(self.remove(at: oldIndex), at: newIndex)
    }

but this is not working properly. Any better way to do this in swift ?

Mutating the list your sorting, in the middle of sorting... yikes — Alexander, Dec 07 '17 at 20:04

Martin R · Accepted Answer · 2017-12-08T10:53:28.533

2

Your approach is far too complicated. You have two sorting criteria:

isIncluded – true values should be sorted before false values,
lastupdatedTime – larger values should be sorted first.

That can be done with a single sort() call:

conversationList.sort(by: { 
    if $0.isIncluded != $1.isIncluded {
        return $0.isIncluded
    } else {
        return $0.lastupdatedTime > $1.lastupdatedTime
    }
})

This assumes isIncluded is a boolean variable (which would be sensible). If it is an integer (as you indicated in the comments) then it is even simpler: (compare Swift - Sort array of objects with multiple criteria):

conversationList.sort(by: {
    ($0.isIncluded, $0.lastupdatedTime) > ($1.isIncluded, $1.lastupdatedTime)
})

edited Dec 08 '17 at 10:53

answered Dec 07 '17 at 20:18

Martin R

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Sorting is working fine but sometimes isIncluded true values comes at the top and sometime false value. I updated the first if condition to "if $0.isIncluded != $1.isIncluded && $0.isIncluded ! == false" and it didn't worked. :-| – aqsa arshad Dec 08 '17 at 06:04
Consider isIncluded values 1,0 instead of true false. 1 values should be at top and 0 values should be at bottom. – aqsa arshad Dec 08 '17 at 06:06
@aqsaarshad: What type has `isIncluded`? What is `isIncluded1` ? – Martin R Dec 08 '17 at 06:07
'isIncluded' is of type int. And i have edited my comment. – aqsa arshad Dec 08 '17 at 06:08
Then `return $0.isIncluded > $1.included` in the first case. – Martin R Dec 08 '17 at 06:10
My bad, problem was in my data. For hardcode data its working fine. Thanks. – aqsa arshad Dec 08 '17 at 06:16

Move some objects of array at the end in swift 3

1 Answers1