Bash_test_expressions Cheat Sheet by andrsrz

Instead of using [ expre­ssion ] is going to be [[ expre­ssion ]] and one designed for integers is (( expre­ssion )).

With [[ expre­ssion ]] we can have an expression matching a regular expres­sion:
string =~ regex.

For the integers in this way we can use the conven­tional way of other progra­mming languages expres­sions like:
int == 0.
int < 0.
int > 0.
int % 0.

And of course the logical operators, instead of using the older options of test we can use:
&& for and.
|| for or.
! for not.