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How to remove '-' from the array number elements run through this function in JS?

December 17, 2022

I’m using this function below to sum "columns" of a 2D Array, but some elements contain '-' and I haven’t been able to handle it:

I’ve tried Number(num) or typeof num === 'number', but still…

const arr = [
   ['-', 2, 21],
   [1, '-', 4, 54],
   [5, 2, 2],
   [11, 5, 3, 1]
];

 const sumArray = (array) => {
   const newArray = [];
   array.forEach(sub => {
      sub.forEach((num, index) => {
         if(newArray[index]){
            newArray[index] += num;
         }else{
            newArray[index] = num;
         }
      });
   });
   return newArray;
}
console.log(sumArray(arr))

>Solution :

Try:

const arr = [
  ['-', 2, 21],
  [1, '-', 4, 54],
  [5, 2, 2],
  [11, 5, 3, 1]
];

const sumArray = (array) => {
  const newArray = [];
  array.forEach(sub => {
    sub.forEach((num, index) => {
      if (typeof num == 'number') {
        if (newArray[index]) {
          newArray[index] += num;
        } else {
          newArray[index] = num;
        }
      }
    });
  });
  return newArray;
}
console.log(sumArray(arr))

Here’s a more concise solution:

const arr = [
  ['-', 2, 21],
  [1, '-', 4, 54],
  [5, 2, 2],
  [11, 5, 3, 1]
];

const result = arr.map((e, i) => arr.reduce((a, c) => (typeof c[i] == 'number' ? a + c[i] : a), 0))
console.log(result)