8. 字符串转换整数 (atoi)

/**
 * @param {string} s
 * @return {number}
 */
var myAtoi = function (s) {
  const MAX_VALUE = 2 ** 31 - 1
  const MIN_VALUE = -(2 ** 31)
  let result = parseInt(s)
  if (Number.isNaN(result)) {
    result = 0
  } else if (result > MAX_VALUE) {
    result = MAX_VALUE
  } else if (result < MIN_VALUE) {
    result = MIN_VALUE
  }
  return result
}