How to concat 2 arrays, based on index

Question

I would like to merge 2 arrays:

arr1 = [["apple"], ["banana", "cherry"]]
arr2 = ["id1", "id2"]

I would like to get the output like:

result = [["apple id1"], ["banana id2", "cherry id2"]]

or

result = [["apple from id1"], ["banana from id2", "cherry from id2"]]

I have tried concat, but this is not keeping me the ID for each element. I am new in development overall, and I didn't find so far any results that would give me the proper output. Any hint how can I do this?

Answer 1

Array#map is what you need.

arr1 = [["apple"], ["banana", "cherry"]]
arr2 = ["id1", "id2"]

var result = arr2.map((id, idx) => {
  return arr1[idx].map(item => item + " from " + id);
})

console.log(result);

Answer 2

You could map the new items.

var arr1 = [["apple"], ["banana", "cherry"]],
    arr2 = ["id1", "id2"],
    result = arr1.map((a, i) => a.map(v => [v, arr2[i]].join(' ')));

console.log(result);