How do I use a core data Integer 64 property?

Question

I want to have an Entity property in Core Data be a 64-bit integer. Since the model is going to run on iOS, and as far as I know these devices are not 64-bit, I figured that `NSNumber` was the way to go (core data gives you the option of objects or scalar properties for primitive types). I'm assuming that `NSNumber` will internally take care of keeping track of a suitable representation for 64 bits. Now, I need to subtract 1 from this "64 bit" property in my entity at some point (in case you didn't guess, the 64 bit property is the max_id parameter in the Twitter API), but to do so, I first need to unbox the number inside the NSNumber property. So should i get the intValue? longValue? unsignedIntValue? unsignedLongValue? long long? which one?

Accepted Answer

Since you already know the type (64 bit integer), you don't need to check for it.

To get a 64 bit integer out of a NSNumber, do one of the following:

```
NSInteger myInteger = [myNSNumber integerValue];
int64_t   myInteger = [myNSNumber integerValue];
```

In order to just add one to it, you can use something like this:

```
myNSNumber = [NSNumber numberWithInteger:[myNSNumber integerValue]+1]];
```

Note that iOS does have 64 bit data types like `int64_t` and `NSInteger`.

EDIT: If the only reason that you are using `NSNumber` is to store the 64 bit integer, you can just declare the property like this in your model subclass and skip the unboxing/boxing altogether:

```
@property (nonatomic) int64_t myIntValue;
```

Note that core data does this by default if you select the Use scalar properties for primitive data types option of the Create NSManagedObject Subclass feature.

How do I use a core data Integer 64 property?

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