Question about collision with multiple types of objects

Hello,

Currently i have a game with one enemy and one bullet. Im planning on making more but while thinking this trough i stumbled uppon a problem.

Lets say i put all my enemy in an array and all my bullets in an array. How do i check collision for my enemy with all the possible bullets that can be on stage.

Currently i would do it by checking each enemy to all kinds of possible types of bullets, but that seems quite some overkill to me since it would require massive array checking loops.

Can anyone point me into the right direction as how to solve this problem?

Regards,
TurboTuTone