You have just purchased your first Mac and are looking for the square brackets on the keyboard? Quickly you will notice that the keyboard of a Mac of Windows-different computers - the square brackets are missing on the Mac keyboard. So you are [ and ] but to create anyway.
Surround it with the brackets
With a simple key combination, you put the square brackets depending on your needs.
- To put the to the right open bracket " [ " , press the keys [Alt] and  simultaneously. The right place open parenthesis at the Position of the activated text.
- You want to close the bracket "]", press the [Alt] key and the  key at the same time.
Also other special characters must be set to the Mac keyboard, certain key combinations. Read more in this practical tip
under point 5.