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

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))

CodePudding user response：

You could use map and reduce to achieve this as well.

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

const sums = arr.map((sub) =>
  sub.reduce((previous, current) => {
    // check here that the value is a number
    if (typeof current === 'number') {
      return previous   current;
    }

    return previous;
  }, 0)
);

console.log(sums);

// returns [23, 59, 9, 20]

CodePudding user response：

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)

CodePudding user response：

Using splice() would help remove the - from the array