I managed to introduce the first array into the second in the correct order but I can’t figure it out how to remove the brackets/quotes.
Can I please get some help?
There are few things you need to clean up in order to pass.
The first thing is here
you can remove this because it is not needed. Having it there is giving you the wrong result like this
[ 4, '1,2,3', 5 ]
[ '1,2,3,4' ]
Once you remove that, that leaves you having to figure out what really should go here for that 3rd argument
What you want to do is copy over each individual item from arr1 into that modifed slicey array. My guess is that is why you were trying toString in the first place.
I would suggest googling "how to insert all elements from copied array splice js"
or something to that affect.
You will get tons of results on how to get all of the individual elements from the copied array.