1
var isValid = function (s) {
2
  const stack = [];
3

4
  for (let i = 0; i < s.length; i++) {
5
    let c = s.charAt(i);
6
    switch (c) {
7
      case "(":
8
        stack.push(")");
9
        break;
10
      case "[":
11
        stack.push("]");
12
        break;
13
      case "{":
14
        stack.push("}");
15
        break;
16
      default:
17
        if (c !== stack.pop()) {
18
          return false;
19
        }
20
    }
21
  }
22

23
  return stack.length === 0;
24
};