Do some DSLR's omit a zoom button?

My Nikon d7100 does not seem to have a dedicated zoom button

is that normal?

Added (1). zoom to shoot

Do you mean zoom to view or zoom to shoot? To shoot is done manually on DSLR cameras, unlike bridge and point and shoot.

SLRs zoom with a ring on the lens. Read your manual.

No DSLRs have a "zoom button". You need to turn the zoom ring manually, it's located on the lens - if it's a zoom lens. If it's a prime lens, like a 50mm f/1.4 then there's no zoom at all. You'll need to use leg zoom.

Joedh has made the most important point here - you really do need to read your user manual.

You bought a mid-level camera and don't know that?
Only point and shoot cameras have a zoom button.

Head / desk…

Oh for crying out loud!

a "zoom button" on a dslr, now I have heard it all.