In the interest of saving someone else some grief, here’s how to decode
long long (64-bit) integers in Objective-C:
long long veryLong = 0;
[[NSScanner scannerWithString:@"100001621738699"] scanLongLong:&veryLong];
NSLog(@"Checking '100001621738699': %qi", veryLong);
One usually runs into
long longs when dealing with Facebook Ids. I’ve written on this before, here.