Integer

Swift	Kotlin	Size (bits)
Int		Same size as the current platform’s native word size.
Int8	Byte	8
Int16	Short	16
Int32	Int	32
Int64	Long	64

Swift

var integer: Int = 0
var 8BitsInteger: Int8 = 0
var 16BitsInteger: Int16 = 0
var 32BitsInteger: Int32 = 0
var 64BitsInteger: Int64 = 0

Kotlin

var 8BitsInteger: Byte = 0
var 16BitsInteger: Short = 0
var 32BitsInteger: Int = 0
var 64BitsInteger: Long = 0