I learned arrays by playing around.
Make a new .capx and test this out.
Add array, touch, sprite1, sprite2.
Make your array 3,1,1
On start of layout:
set value of x 0 to 100 (array, set at x)
set value of x 1 to 400
set value of x 2 to 200
on touch sprite1: sort array
on touch sprite2: reverse array
Then run this in debugger preview (that way you can see how the array changes as you click)