Returns an index that is the specified distance from the given index.
func index(_ i: Int, offsetBy distance: Int) -> Int
A valid index of the array.
The distance to offset
An index offset by
distance from the index
distance is positive, this is the same value as the result of
distance calls to
distance is negative, this is the same value as the result of
abs(distance) calls to
The following example obtains an index advanced four positions from an array’s starting index and then prints the element at that position.
let numbers = [10, 20, 30, 40, 50] let i = numbers.index(numbers.startIndex, offsetBy: 4) print(numbers[i]) // Prints "50"
The value passed as
distance must not offset
i beyond the bounds of the collection.