Commenting blocks in Eclipse on Mac

Solution 1:

Apple + Shift + / will toggle a block of selected code using /* */
Apple + / will toggle a line (or multiple, if selected) using //

You may have to disable the OS hotkey (apple + shift + / brings up the help menu)

Solution 2:

Ctrl + cmd + / <- block comment and Ctrol + cmd + \ <- remove comment

Solution 3:

Command (the clover/apple key next to the space bar) forward slash (/)