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iOS Error Handling in Swift Error Handling Cleaning Up With Defer

Posted by Lorenzo Gonzalez
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Lorenzo Gonzalez
iOS Development Techdegree Student 4,648 Points

Absence of "throw"

Why isn't there a "throw" in the second guard statement in this example?

Jeff McDivitt
Jeff McDivitt
23,970 Points

Can you provide the code that you are referring to?

Thanks

Jeff

3 Answers

Matt Skelton
Matt Skelton
4,548 Points

That's a really good spot in my opinion. To my understanding, the guard statement you're referring to should be preceded with the throw keyword.

For reference for anybody interested:

func process(file name: String) throws {
    guard isValidFile(withName: name) else {
        throw ReadError.invalidFile    // <--- throw keyword present
    }

    let file = open(fileName: name)

    guard let line = try file.readLine() else {
        ReadError.unableToReadLine     // <--- throw keyword missing
    }
}

Good vision!

Lorenzo Gonzalez
.a{fill-rule:evenodd;}techdegree
Lorenzo Gonzalez
iOS Development Techdegree Student 4,648 Points

Thanks for providing the code snippet!

hannah echo
hannah echo
2,872 Points
hannah echo
hannah echo
2,872 Points

throw isn't required here because of the use of the try keyword

Shaan Marok
PLUS
Shaan Marok
Courses Plus Student 1,015 Points
Shaan Marok
Shaan Marok
Courses Plus Student 1,015 Points

it's a typo. It should be there.

Olivier Van hamme
Olivier Van hamme
5,418 Points

I agree. It must be a typo. At 2:02 Pasan is talking about the second throw statement. He literary mentions it:

From the video transcript:

" … Or in the case of the second throw statement, when we immediately hid that … "

Copy pasting this from the transcript, I discovered another typo: hid instead of hit ?