How do you flatten an array? That is, how do you take something like this:
[1, [2, [3, [4]]]]
and change it into something like this?
[1, 2, 3, 4]
The first thing that occurs to me is that you would go through each element of the given array and check to see whether it is an array. So we go through:
1 (NO)
[2, [3, [4]]] (YES)
We're done with the non-arrays -- we can keep them somewhere (another array) but the arrays require further processing. We process them in exactly the way we processed the first array. The trick is figuring out how to do that organically: we need the computer to keep processing elements of the array and members of those members recursively (!) on down to the elements.
What I think you would do is create a general function that processes an array into elements, then call that function not only on the array itself, but on the members of that array. How would that look?
Well, if we have an element, we don't call it. But if we have an array, we do call it. It gives us back a result that we can parse through, saving the good stuff and continuing to process the bad stuff. So for that second element processing would look like this:
[2, [3, [4]]] -- Call =>
2, [3, [4]] -- Keep 2 =>
[3, [4]] -- Call =>
3, [4] -- Keep 3 =>
[4] -- Call
4 -- Keep 4
DONE!
So in short, the function returns an array, which we loop through, keeping all the items that are non-arrays and processing the rest. How does it return that array? It just loops through the items and stores them, I guess -- nothing fancy.
I'll update as I think more about this -- I think this is on the right track, but I'm not yet convinced it would work. Maybe there's some way to do it with just loops so that you don't have to bother with recursive functions at all...
[1, [2, [3, [4]]]]
and change it into something like this?
[1, 2, 3, 4]
The first thing that occurs to me is that you would go through each element of the given array and check to see whether it is an array. So we go through:
1 (NO)
[2, [3, [4]]] (YES)
We're done with the non-arrays -- we can keep them somewhere (another array) but the arrays require further processing. We process them in exactly the way we processed the first array. The trick is figuring out how to do that organically: we need the computer to keep processing elements of the array and members of those members recursively (!) on down to the elements.
What I think you would do is create a general function that processes an array into elements, then call that function not only on the array itself, but on the members of that array. How would that look?
Well, if we have an element, we don't call it. But if we have an array, we do call it. It gives us back a result that we can parse through, saving the good stuff and continuing to process the bad stuff. So for that second element processing would look like this:
[2, [3, [4]]] -- Call =>
2, [3, [4]] -- Keep 2 =>
[3, [4]] -- Call =>
3, [4] -- Keep 3 =>
[4] -- Call
4 -- Keep 4
DONE!
So in short, the function returns an array, which we loop through, keeping all the items that are non-arrays and processing the rest. How does it return that array? It just loops through the items and stores them, I guess -- nothing fancy.
I'll update as I think more about this -- I think this is on the right track, but I'm not yet convinced it would work. Maybe there's some way to do it with just loops so that you don't have to bother with recursive functions at all...
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