JuniorTheoryCommon

What does the program print (lines separated by spaces)?

SWIFT

enum TextError: Error { case empty }
func letters(in text: String) throws -> Int {
    if text.isEmpty { throw TextError.empty }
    return text.count
}
do {
    print(try letters(in: "ab"))
    print(try letters(in: ""))
    print("end")
} catch {
    print("error")
}

2 error

Expecting 2 error end: thinking the do block goes on after catch. An error skips the rest of do for good, and after catch the program continues below it.
Expecting error alone: thinking a do block runs only when none of its lines throws. Its lines run in order, so 2 is printed before the error.

What would the program print if print("end") stood after the closing brace of catch?
How would you change the second call so that empty text gives 0 instead of reaching catch?

Back to questions Open topic in roadmap →Answer it yourself — Quiz

Back to questions

JuniorTheoryCommon

What does the program print (lines separated by spaces)?

SWIFT

enum TextError: Error { case empty }
func letters(in text: String) throws -> Int {
    if text.isEmpty { throw TextError.empty }
    return text.count
}
do {
    print(try letters(in: "ab"))
    print(try letters(in: ""))
    print("end")
} catch {
    print("error")
}

2 error

Expecting 2 error end: thinking the do block goes on after catch. An error skips the rest of do for good, and after catch the program continues below it.
Expecting error alone: thinking a do block runs only when none of its lines throws. Its lines run in order, so 2 is printed before the error.

What would the program print if print("end") stood after the closing brace of catch?
How would you change the second call so that empty text gives 0 instead of reaching catch?

Back to questions Open topic in roadmap →Answer it yourself — Quiz