ios - Convert NSNumber to long

Question

I am trying to convert a NSNumber to long but I get this error:

[__NSSingleObjectArrayI intValue]: unrecognized selector sent to instance

Here is my code:

NSNumber *dbversion = [settings valueForKey:@"Version"];
long dbver = [dbversion longValue];

What am I doing wrong here?

*settings is a NSArray and "Version" is the key for a long value.

Answer 1

You are caught in the Key-Value Coding trap.

In some cases the result of valueForKey is an array which the error message clearly states.

Don't Never use valueForKey(unless you know what KVC does and you need KVC), use key subscription.

And as settings is an array you might get the first item

NSNumber *dbversion = settings[0][@"Version"];

and int is not long

long dbver = [dbversion longValue];

However on a 64-bit machine I recommend to use NSInteger

NSInteger dbver = dbversion.integerValue;