Those are not different datatypes.
When you see the same array displaying 7.00000000000000 and 7 both, then what it tells you is that the 7 value is exactly the floating point representation of 7, but that the 7.00000000000000 value is slightly different from 7 exactly. If you were to take Array(7) - Array(8) you would see a very small difference, probably roughly 2E-15 . The value that is exactly 7.0000000000000017763568394002504646778106689453125 displays as 7.00000000000000 in some cases because the default formats do not display all of the digits.
