Returns a string with inversed cases

caseInverse.js

/**
 * Returns a string with inversed cases
 * @param {String} string The 'string' to inverse the cases of its characters
 */
const caseInverse = string => {
  let inversedString = '';
  for (const letter of string) {
    if (letter.toUpperCase() === letter) {
      inversedString += letter.toLowerCase()
    } else {
      inversedString += letter.toUpperCase()
    }
  }

  return inversedString;
}

module.exports = caseInverse;