exclamation point after try - try!

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Created Sep ’17

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What does it mean when I see an exclamation point after the "try" statement like the following code? Is it unwrapping the result of the statement?

                            do {
                                try! cnContactStore.execute(saveRequest)
                            } catch let error as NSError {
                               
                                print(error)
                               
                            }

Answered by ShinehahGnolaum in 261923022

Got it! In documentation for Swift:

Disabling Error Propagation

Sometimes you know a throwing function or method won’t, in fact, throw an error at runtime. On those occasions, you can write

try!

before the expression to disable error propagation and wrap the call in a runtime assertion that no error will be thrown. If an error actually is thrown, you’ll get a runtime error.

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ShinehahGnolaum OP

Sep ’17

Accepted Answer

Got it! In documentation for Swift:

Disabling Error Propagation

Sometimes you know a throwing function or method won’t, in fact, throw an error at runtime. On those occasions, you can write

try!

before the expression to disable error propagation and wrap the call in a runtime assertion that no error will be thrown. If an error actually is thrown, you’ll get a runtime error.

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