How to separate arrayed objects? This question seems to be asked before but the answer did not work for me.

I arrayed an object using an empty and a cube.

Then I changed mode to Edit to use Separate by typing P.

As suggested I tried to select all object before doing this.

But when type A only one object has been selected in edit mode the original object I used to create the array.

After that I used P then the clicked the By Loose Parts and went

back to the Object Mode and select one object, vala, all the object in array has been selected.

What is the reason it is not working.
You need to apply your Array modifier, once done you'll be able to separate the objects.