Balanced Brackets

const input = ["[[)}", "{()}"]

const balanceBrackets = arr => {
  
  const result = arr.map(string => {
    const stack = [];
    const map = {
      '(': ')',
      '[': ']',
      '{': '}'
    }

    for (let i = 0; i < string.length; i++) {
      if (string[i] === '(' || string[i] === '{' || string[i] === '[' ) {
          stack.push(string[i]);
        } 
        else {
          if (string[i] !== map[stack.pop()]) return 'NO'
        }
    }
    if (stack.length !== 0) return 'NO'
    return 'YES';
  })
  return result
}

balanceBrackets(input)