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Start your free trialGene Bogdanovich
14,618 PointsCountableRange Question
Consider this code:
let greeting = "hello world"
if let firstSpace = greeting.index(of: " ") {
let secondWordIndex = greeting.index(firstSpace, offsetBy: 1)
let secondWord = greeting[secondWordIndex..<greeting.endIndex] // "world"
}
Why do we use half-open range operator (..<) instead of closed range operator (…) to get the second word?
1 Answer
Addison Francisco
9,561 PointsHey Gene,
A half-open range operator is required in this example because you are subscripting with String.endIndex
which returns the index after the last character in the collection. For your example, you want the index right before that. Using a half-open range operator achieves just that. Alternatively, you could use index(before:)
with a closed range operator to achieve the same result
let secondWord = greeting[secondWordIndex...greeting.index(before: greeting.endIndex)]
Gene Bogdanovich
14,618 PointsGene Bogdanovich
14,618 PointsThank you very much! That surely cleared things up for me.