Selecting every single unit from a certain type in StarCraft 2

Solution 1:

To expand on alicsharp's answer:

You can press the all-army hotkey (F2 by default), then CTRL+Click on the any unit of the type you want to select in the command card at the bottom. If you are using Mac, and you've set the setting that makes CMD act as CTRL, say, for setting command groups, then instead of CTRL+Click, you should use CMD+Click.

Solution 2:

The TAB key does this.

TAB does select each unit type but there is no hotkey for every unit of a type. You would have to use F2 first to select your whole army and then use tab to cycle through each type of unit in your army. -- Enhanced instructions from Mac Man on how to actually cycle through the units.