gistfile1.txt

function isBalanced(string) {
  let stack = [];
  let character;
  let parenthesesPos;
  for (var i = 0; character = string[i]; i++) {
    parenthesesPos = parentheses.indexOf(character);
    if(parenthesesPos === -1) {
      continue;
    }
    if(parenthesesPos % 2 === 0) {
      stack.push(parenthesesPos + 1);
    }
    else {
      if(stack.length === 0 || stack.pop() !== parenthesesPos) {
        return false
      }
    }
  }
  return stack.length === 0;
}
console.log(isBalanced('[]{}()'));
console.log(isBalanced('[]{}{[]()}'));
console.log(isBalanced('[(])'));