Iterate over specific indexes of a given string

Using Swift
1

How can I iterate over specific indexes of a given string? Let's say I want to print characters for indexes numbers 2,4,6,8 of a given string.

2

Note that Swift makes a distinction between indices and offsets. A Collection guarantees fast access from its Index, but you usually need to traverse a portion of the collection to access a specific offset. There is an exception where a collection's index is the same as its offset, e.g. Array.

Back onto the topic, If it's a one-off thing, you can enumerate the string:

for (offset, character) in string.enumerated() where offset.isMultiple(of: 2) {
  ...
}

You can change the condition to whatever you'd like. If you do this multiple times, and the condition is non-trivial, you could also convert the string to an Array.

let array = Array(string)

array[0] = ...
array[2] = ...
...
5

thank you