Convert integer into its character equivalent, where 0 => a, 1 => b, etc

Question

I want to convert an integer into its character equivalent based on the alphabet. For example:

0 => a
1 => b
2 => c
3 => d

etc.

Answer 1

I don't like all the solutions that use magic numbers like 97 or 36.

const A = 'A'.charCodeAt(0);

let numberToCharacter = number => String.fromCharCode(A + number);

let characterToNumber = character => character.charCodeAt(0) - A;

this assumes uppercase letters and starts 'A' at 0.