Java balanced expressions check {[()]}

Question

I am trying to create a program that takes a string as an argument into its constructor. I need a method that checks whether the string is a balanced parenthesized expressio

Answer 1

public static boolean isBalanced(String expression) {
  if ((expression.length() % 2) == 1) return false;
  else {
    Stack s = new Stack<>();
    for (char bracket : expression.toCharArray())
      switch (bracket) {
        case '{': s.push('}'); break;
        case '(': s.push(')'); break;
        case '[': s.push(']'); break;
        default :
          if (s.isEmpty() || bracket != s.peek()) { return false;}
          s.pop();
      }
    return s.isEmpty();
  }
}

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String expression = in.nextLine();
    boolean answer = isBalanced(expression);
    if (answer) { System.out.println("YES");}
    else { System.out.println("NO");}

}