// 拼接字符串
const padStart = (
  string: string | number,
  targetLength: number,
  padString: string
) => {
  targetLength = targetLength >> 0;
  string = String(string);
  padString = String(padString);

  if (string.length > targetLength) {
    return String(string);
  }

  targetLength = targetLength - string.length;

  if (targetLength > padString.length) {
    padString += padString.repeat(targetLength / padString.length);
  }

  return padString.slice(0, targetLength) + String(string);
};

export default (n: string | number, length = 2) => padStart(n, length, '0');