[CodeKata] 문자열 다루기 기본

링크

• https://programmers.co.kr/learn/courses/30/lessons/12918

참고

• https://stackoverflow.com/questions/55724674/how-to-check-for-exponential-values-in-javascript
• https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_objects/Number/toPrecision

나의 풀이

function solution(s) {
  const num = Number(s);
  const precision = s.length === 4 ? num.toPrecision(4) : num.toPrecision(6);

  const result =
    (isNaN(precision) !== true && precision.length === 4) ||
    precision.length === 6
      ? true
      : false;
  return result;
}

정규식... 😱

function solution(s) {
  const regex = /^\d{6}$|^\d{4}$/;
  return regex.test(s);
}