balanced-parenthesis.js

console.clear()

function isBalanced(input) {  
  let stack = []
  const length = input.length

  for (let i = 0; i < length; i++) {
    if (input[i] === '(') {
      stack.push('(')
    } else {
      stack.pop();
    }
  }
  
  return stack.length === 0
}

console.log(
  isBalanced('(())(())())')
)