How to remove all items that matches index in myindexes array in Swift

Question

I have a itemArray, and I need remove all item index that contained in another array indexArray.

list = ["1", "2", "3", "4", "5"]
rows = [2, 4]

for i in rows {
   list.remove(at: i)
}

I do want to remove "3", "5", but the above code will be crash. I need set rows = [4, 2], remove to worked well

This came up recently on the Swift forums: https://forums.swift.org/t/implementing-a-collection-removingindicies/27681?u=alexanderm — Alexander, Aug 08 '19 at 03:10
@Alexander thank you for telling, this is really a good thing. — symbool, Aug 08 '19 at 06:27
you can refer this too : https://stackoverflow.com/a/42872151/7301439 — Saifan Nadaf, Aug 08 '19 at 06:50

PGDev · Answer 1 · 2019-08-08T10:31:05.820

0

Your code is crashing because after you're delete the element at index-2, the elements count in array is reduced. Hence, when deleting element at index-5, it results in runtime exception "Index out of bounds".

So, you need to sort the rows array in decreasing order and then delete the elements from list one by one, i.e.

var list = ["1", "2", "3", "4", "5"]
var rows = [2, 4]
rows.sorted(by: >).forEach({ list.remove(at: $0) })
print(list) //["1", "2", "4"]

edited Aug 08 '19 at 10:31

answered Aug 08 '19 at 07:32

PGDev

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You can simplify it with `sorted(by: >)` – Alexander Aug 08 '19 at 10:30
Is the issue resolved? – PGDev Aug 14 '19 at 16:26
Yep, looks good. I would also omit the https://www.google.com/search?client=safari&rls=en&q=parentheses&ie=UTF-8&oe=UTF-8 and use trailing closure syntax: `.forEach { list.remove(at: $0) }`. Optionally, you could use partial method application instead: `.forEach(list.remove(at:))` – Alexander Aug 14 '19 at 16:51

How to remove all items that matches index in myindexes array in Swift

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