Slice and Splice console says it's right but won't pass?

Tell us what’s happening:
I tested the results in the console and it yields the same results when I paste the basic solution to replace my code.

“All elements from the first array should be added to the second array in their original order.”
Does this mean I have to add each element one by one, as in a loop? Even if that’s the case, I don’t see why my test cases are returning false.

"frankenSplice([1, 2, 3], [4, 5], 1) should return [4, 1, 2, 3, 5]"
There is still a cross against these even though when I console.log arr3 it prints the correct array.

Your code so far

function frankenSplice(arr1, arr2, n) {
  // It's alive. It's alive!
  let arr3 = arr2.slice();
  arr3.splice(n, 0, arr1);

  return arr3;

frankenSplice([1, 2, 3], [4, 5, 6], 1);
frankenSplice([1, 2, 3], [4, 5], 1)
frankenSplice([1, 2], ["a", "b"], 1)
frankenSplice(["claw", "tentacle"], ["head", "shoulders", "knees", "toes"], 2) 

You are creating a multi-dimensional (or “nested”) array. You need to return a flat array.

Ah so that’s what it was. Thanks, I was totally thrown off by that console.