将String强制转换为Int64会导致32位设备崩溃

Question

I have to deal with a pretty long Int, that comes to me as a String. Calling Int64(String) works fine on 64bit devices, but I see crashes on 32bit devices. What is the reason for this?

Here is the code:

let predicateBarcode = NSPredicate(format: "barcode = %ld", Int64(searchTerm)!)

I cannot tell anything about the searchterm, it comes from the barcode scanner and is an ean-13. I can also not reproduce the crash, as this is only happening to my costomers.

Answer 1

It's not the problem of Int64.init(_:) but the problem of the format given to NSPredicate .

Length specifier l means its argument needs to be long or unsigned long , which are equivalent to Int or UInt in Swift.

String Format Specifiers

If you want to use Int64 value as a format argument, the right length specifier is ll , meaning long long which is equivalent to Int64 in Swift.

let predicateBarcode = NSPredicate(format: "barcode = %lld", Int64(searchTerm)!)

You may need to fix some other parts, but I cannot see as you are hiding other parts. (And as far as I test, I could not make my testing app crash.) In addition, are you 100%-sure about Int64(searchTerm)! may not crash?

Anyway, the format string needs to be fixed at least.