iOS Swift – Difference Between Int and Integer in Swift

intiosswift

Does anyone know what the difference is between these two types?

The docs only refer to Int but Xcode 6 auto complete only gives me Integer when I type. I started using Integer when porting code only to find that you have to cast between the two types.

For instance the following code gives the error Could not find an overload for '+' that accepts the supplied arguments.

var number1 : Int = 5
var number2 : Integer = 10
number1 + number2

Best Answer

An Int is the type whilst an Integer is a protocol it implements.

You should be using Int in declarations, i.e:

var num: Int = 5

which is also the type that's inferred for integer literals when a type isn't specified, i.e:

var num = 5

Related Solutions

iOS Objective-C – When to Use NSInteger vs int

You usually want to use NSInteger when you don't know what kind of processor architecture your code might run on, so you may for some reason want the largest possible integer type, which on 32 bit systems is just an int, while on a 64-bit system it's a long.

I'd stick with using NSInteger instead of int/long unless you specifically require them.

NSInteger/NSUInteger are defined as *dynamic typedef*s to one of these types, and they are defined like this:

#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif

With regard to the correct format specifier you should use for each of these types, see the String Programming Guide's section on Platform Dependencies

Swift – Difference Between Int and Int32

According to the Swift Documentation

Int

In most cases, you don’t need to pick a specific size of integer to use in your code. Swift provides an additional integer type, Int, which has the same size as the current platform’s native word size:

On a 32-bit platform, Int is the same size as Int32.

On a 64-bit platform, Int is the same size as Int64.

Unless you need to work with a specific size of integer, always use Int for integer values in your code. This aids code consistency and interoperability. Even on 32-bit platforms, Int can store any value between -2,147,483,648 and 2,147,483,647, and is large enough for many integer ranges.

Best Answer

Related Solutions

iOS Objective-C – When to Use NSInteger vs int

Swift – Difference Between Int and Int32

Int

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