LeetCode: Evaluate Reverse Polish Notation Solution

1/**
2 * @param {string[]} tokens
3 * @return {number}
4 */
5var evalRPN = function (tokens) {
6  const s = []
7  let a, b
8  for (const token of tokens) {
9    switch (token) {
10      case "+": {
11        ;[a, b] = [s.pop(), s.pop()]
12        s.push(a + b)
13        break
14      }
15      case "-": {
16        ;[a, b] = [s.pop(), s.pop()]
17        s.push(b - a)
18        break
19      }
20      case "*": {
21        ;[a, b] = [s.pop(), s.pop()]
22        s.push(a * b)
23        break
24      }
25      case "/": {
26        ;[a, b] = [s.pop(), s.pop()]
27        s.push(Math.trunc(b / a))
28        break
29      }
30      default: {
31        s.push(Number(token))
32      }
33    }
34  }
35  return s.pop()
36}