epranka

// Type definitions

type Split<S extends string, D extends string> = string extends S
  ? string[]
  : S extends ''
  ? []
  : S extends `${infer T}${D}${infer U}`
  ? [T, ...Split<U, D>]
  : [S];

epranka

let a = '5';

a = +a; // convert it to a number

console.log(a, typeof a); // 5 number

a = ''+a; // convert it back to a string

console.log(a, typeof a); // '5' string