On the paragraph explaining arithmetic expansion, Bash's user guide uncovers 2 different ways of evaluating an expression, the first one uses
$(( EXPRESSION )) and the second one uses
$[ EXPRESSION ]. The two ways seem pretty similar as the only difference I have found is:
$[ EXPRESSION ]will only calculate the result of EXPRESSION, and do no tests:
Yet, I am intrigued because the same document recommends using
$[ EXPRESSION ] rather than
$(( EXPRESSION )).
Wherever possible, Bash users should try to use the syntax with square brackets:
Why would you want that if less tests are being done?