Evaluate Reverse Polish Notation LeetCode solution in JavaScript

1
const ops = new Set(["+", "-", "*", "/"]);
2

3
/**
4
 * @param {string[]} tokens
5
 * @return {number}
6
 */
7
var evalRPN = function (tokens) {
8
  const stack = [];
9

10
  for (const token of tokens) {
11
    if (!ops.has(token)) {
12
      stack.push(Number(token));
13
      continue;
14
    }
15

16
    const val1 = stack.pop();
17
    const val2 = stack.pop();
18
    let toPush;
19

20
    if (token === "+") {
21
      toPush = val1 + val2;
22
    }
23

24
    if (token === "-") {
25
      toPush = val2 - val1;
26
    }
27

28
    if (token === "*") {
29
      toPush = val1 * val2;
30
    }
31

32
    if (token === "/") {
33
      toPush = Math.trunc(val2 / val1);
34
    }
35

36
    stack.push(toPush);
37
  }
38

39
  return stack[0] || 0;
40
};