withIndex
fun CharSequence.withIndex(): Iterable<IndexedValue<Char>>Returns a lazy Iterable that wraps each character of the original char sequence into an IndexedValue containing the index of that character and the character itself.
fun CharSequence.withIndex(): Iterable<IndexedValue<Char>>Returns a lazy Iterable that wraps each character of the original char sequence into an IndexedValue containing the index of that character and the character itself.