Exercise to check if string of brackets is balanced or nah..

balanced-brackets.js

const isBalanced = (s) => {
  const stack = [];
  const charArray = s.split("");

  for (const [index, char] of charArray.entries()) {
    switch (char) {
      // insert
      case "(":
      case "[":
      case "{":
        stack.push(char);
        break;
      // remove (
      case ")": {
        const last = stack.pop();
        if (last !== "(") {
          return false;
        }
        break;
      }
      // remove [
      case "]": {
        const last = stack.pop();
        if (last !== "[") {
          return false;
        }
        break;
      }
      // remove {
      case "}": {
        const last = stack.pop();
        if (last !== "{") {
          return false;
        }
        break;
      }
      default:
        break;
    }
  }

  return !stack.length;
};

const testCases = [
  "())", // false
  "(())", // true
  "{[(])}", // false
  "{[()]}", //true
  "{[()[]]}", //true
];

for(const test of testCases){
  console.log(`is "${test}" balanced?: `, isBalanced(test) ? 'yes' : 'no');
}