How can I add two arrays?

Question

How can I add two arrays?
https://code.sololearn.com/WDSv8v27I8Ry/?ref=app
(Plus + wont work)

Answer 1

Its interesting thing, that such adding arrays causes adding commas in array

Answer 2

arr = arr1.concat(arr2);

Answer 3

You can add the elements of arrays having the same index
...

Answer 4

You can simply use loop to add two arrays as
var arr1= [1, 3];
var arr2 = [2, 4];
var set= [];

for(var i= 0; i<arr1.length; i++){
set[i]= arr1[i] + arr2[i];
console.log(set[i]);
}

Answer 5

https://code.sololearn.com/WLnxbX0oXadq/?ref=app

Answer 6

var arr1=[1,3] //arr1
var arr2=[2,4] //arr2
arr1=arr1.join("") //change arr1 to String without the qoma
arr2=arr2.join("") // Same arr1
arr1=arr1.concat(arr2) //to gather them as string
const [...set]=arr1 //to change it to string again
alert(set) //see
set.forEach((e,i)=>{
set[i]=Number(e) //to change each element in set to number
})
console.log(set.reduce((a,b)=>a+b)) //for addition them one by one

Answer 7

The description in the comments