Calc JS Function

calc.js

// TODO: finish

function calc(input) {
  const characters = input.split(''); // ['(', '1', '+', '2', ')']
  let depth = 0;
  const operations = []; // ['1', '+', '2']
  let calculation = [];
  for (let characterIndex = 0; characterIndex < characters.length; characterIndex++) {
    const character = characters[characterIndex];
    if (character === '(') {
      depth++;
    } else if (character === ')') {
      if (characterIndex <= characters.length - 1 && depth > 0) {
        // operations.push(calculation[depth - 1]);
      }
      operations.push(calculation[depth]);
      calculation[depth] = [];
      depth--;
    } else {
      if (calculation[depth]) {
        calculation[depth].push(character);
      } else {
        calculation[depth] = [character];
      }
    }
  }
  console.log(input, operations);
  const filteredOperations = operations.filter(op => op);
  const result = filteredOperations.reduce((output, operation) => {
    if (!operation) return output;
    if (operation[1] === '+') {
      return output + parseInt(operation[2], 0);
    }
    if (operation[1] === '*') {
      return output * parseInt(operation[2], 0);
    }
    return output;
  }, parseInt(filteredOperations[0][0], 0));
  console.log(input, result);
  return result;
}

console.log(calc('(1+2)') === 3);
console.log(calc('(4*6)') === 24);
console.log(calc('((1+2)*(4+4))') === 24);
console.log(calc('(5+(7*3))') === 26);
console.log(calc('(((5+(4*3))*2)+1)') === 35);