LeetCode: Roman To Integer Solution

1/**
2 * @param {string} s
3 * @return {number}
4 */
5var romanToInt = function (s) {
6  s = s.split("")
7  const symbolValue = { I: 1, V: 5, X: 10, L: 50, C: 100, D: 500, M: 1000 }
8  let res = 0
9  for (let i = 0; i < s.length; i++) {
10    if (symbolValue[s[i]] < symbolValue[s[i + 1]]) {
11      res -= symbolValue[s[i]]
12    } else {
13      res += symbolValue[s[i]]
14    }
15  }
16  return res
17}