1

I have code like this

let index = tableView.selectedRowIndexes.map { Int($0) }
        arrDomains.remove(at: index)

But get error

Cannot convert value of type '[Int]' to expected argument type 'Int'

How convert [Int] to int?

In this case, no conversion is needed.
Solution:

let indexes = tableView.selectedRowIndexes.map { Int($0) }
indexes.reversed().forEach { arrDomains.remove(at: $0) }
2

This question is marked as off-topic because it contains API not related to the open source project itself.

I cannot look up the API atm. but judging from what it does, your logic has some issues. The propery returns an [Int] which means that 0 to n cells are selected. You should iterate over the array and decide what to do with each index.

Other than that stdlib has a reduce function to merge each value of the array to a result type.

[1, 2].reduce(3) { $0 + $1 } // returns 6
3

Solution:

let indexes = tableView.selectedRowIndexes.map { Int($0) }
indexes.reversed().forEach { arrDomains.remove(at: $0) }
4 
tableView.selectedRowIndexes
  .map { Int($0) }
  .reversed()
  .forEach { arrDomains.remove(at: $0) }