Size Matters — The Importance of Specific Numeric Types in Swift

Sorting packages. Taken from Pexels.com

In Swift, developers often default to using the Int type for integer variables, driven by its ease of use and direct support for handling typical numeric values within applications. However, the Swift standard library offers a variety of other integer types, such as UInt8, Int16, Int32, Int64, and their unsigned counterparts. Understanding when and why to use these specific integer types instead of the generic Int can lead to more efficient, safe, and appropriate coding practices.

Note: The same goes for Float and Double. For simplicity we will focus on Int.

Efficiency and Memory Usage

One of the primary reasons to choose specific integer types like UInt8 or Int16 is efficiency, particularly regarding memory usage. Each type occupies a different amount of memory:

• UInt8 and Int8 occupy 1 byte,
• Int16 and UInt16 occupy 2 bytes,
• Int32 and UInt32 occupy 4 bytes,
• Int64 and UInt64 occupy 8 bytes.

The default Int type in Swift is platform-dependent—it is 32 bits on 32-bit platforms and 64 bits on 64-bit platforms. For many applications, especially those performing a large number of numerical operations or manipulating large data sets, using a…