try-catch exceptions in Swift [duplicate]

问题

This question already has answers here:

Error-Handling in Swift-Language (12 answers)

Closed 5 years ago.

Is it possible to catch exceptions in Swift? Given the following code:

NSException.raise(NSRangeException,
    format: "Now you've gone too far!",
    arguments: CVaListPointer(fromUnsafePointer: UnsafePointer()))

Is it possible to prevent the exception from crashing the entire program? That is, what is the Swift equivalent of the following in Objective-C:

@try {
    [NSException raise:NSRangeException format:@"Now you've gone too far!"];
}

回答1:

It doesn't have exception handling, and this discussion in the developer forum discusses why it may be so:

but keep in mind that Cocoa and Cocoa Touch traditionally don't intend for you to catch exceptions; they intend for you to not cause them to be thrown in the first place. Ordinary errors should be handled with optional types and inout NSError parameters; you should address any situation that causes an assertion to fail (which seems to be the only exception-throwing mechanism in Swift) by writing better code.

回答2:

I believe that, as of today, Swift does not support this. It will most likely be added on future betas.

来源：https://stackoverflow.com/questions/24023112/try-catch-exceptions-in-swift