CODEWITHSUNDEEP
javascript
Mask
Mask

Reputation: 573

Calculate from last row of an array from another array and push the result in the last row

I have two arrays One 2D and another 1D.

My 2D array has many rows and columns for example:-

My 2D array has arr1 = [[a,b....9],[s,c....12],[x,y....14]] //and so on

My 1D array has arr2 = [3,2,6] // and so on

Now I want to multiply elements of the lastrow of my 2Darr with consecutive 1Darr and divide it by 2 then push the result at the last of the 2D array.

(9*3)/2=13.5

(12*2)/2=12

(14*6)/2= 42

Now my New array should look like this newarr = [[a,b....9,13.5],[s,c....12,12],[x,y....14,42]] // and so on.

Upvotes: 0

Views: 52

Answers (3)

Sven.hig
Sven.hig

Reputation: 4519

arr1 = [["a","b",9],["s","c",12],["x","y",14]],
       arr2 = [3,2,6]
       arr2.map((x,i)=>{arr1.map((y)=>{i===arr1.indexOf(y)?y.push((x*y[y.length-1])/2):null})})
      console.log(arr1)

Upvotes: 1

Nina Scholz
Nina Scholz

Reputation: 386700

You could map the new arrays with the wanted new last value.

const
    arr1 = [["a", "b", 9], ["s", "c", 12], ["x", "y", 14]],
    arr2 = [3, 2, 6],
    result = arr1.map((a, i) => [...a, a[a.length - 1] * arr2[i] / 2]);

console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

Upvotes: 2

Krzysztof Krzeszewski
Krzysztof Krzeszewski

Reputation: 6749

You could just use reduce function to modify the contents of the array on the go and return the new parsed array

const arr1 = [["a","b",9],["s","c",12],["x","y",14]]
const arr2 = [3,2,6]

const result = arr1.reduce((results, element, index) => {
  return [
    ...results, // push the rest of the results onto the new array
    [
      ...element, // keep all the current items of the element (the 1d array)
      element[element.length-1]*arr2[index]/2 // add new element, by querying the last element of the array and the appropriate index of the second array
    ]
  ]
},[] /*initially result being an empty array*/);

console.log(result)

Upvotes: 1

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