Alphabetic Representation of Numbers in Go

Converting a number to a letter in Golang can be achieved in several ways.

Number -> rune

Simply add the number to the constant 'A' - 1 to obtain the corresponding rune:

func toChar(i int) rune {
    return rune('A' - 1   i)
}

Number -> String

If a string is desired, the following function can be used:

func toCharStr(i int) string {
    return string('A' - 1   i)
}

Number -> String (Cached)

To optimize multiple conversions, the corresponding strings can be stored in an array and the array index used to retrieve the string:

var arr = [...]string{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
    "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"}

func toCharStrArr(i int) string {
    return arr[i-1]
}

Number -> String (Slicing String Constant)

An efficient solution involves slicing a string constant:

const abc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

func toCharStrConst(i int) string {
    return abc[i-1 : i]
}

These solutions provide convenient ways to convert numbers to their corresponding alphabetic representations in Go.