find sum of numbers present in elements in nested array

find sum of numbers present in elements in nested array

by gauravkrp

JavaScript

/* sum([1, 'x', '2x', ['3', ['x2', '5']]]); */
const findNumInStringRegex = /\d+/;

const flattenArr = (arr, result = []) => {
  for (let i = 0, length = arr.length; i < length; i++) {
    const value = arr[i];
    if (Array.isArray(value)) {
      flattenArr(value, result);
    } else {
      result.push(value);
    }
  }
  return result;
};

function sum(arr) {
  // const flattenArr = arr.flat(2);
  const flattenedArr = flattenArr(arr);
  let sum = 0;
  
  for (let i = 0; i < flattenedArr.length; i++) {
  	const num = flattenedArr[i];
  	if(typeof num === "number") {
    	sum += num;
    } else {
    	// not number
       const num_ = parseInt(num);
       if(isNaN(num_)) {
          let findNumInString = num.match(findNumInStringRegex);
       		// console.log(num_, num, findNumInString, parseInt(findNumInString));
          if(findNumInString) findNumInString = parseInt(findNumInString);
          sum += findNumInString;
       } else {
         sum += num_;
       }
    }
  }
  return sum;
}

const out = sum([1, 'x', '2x', ['3', ['x2', '5']]]);
console.log(out);