I keep it in single line, if it’s short. Lately I’ve been using this style for longer or nested ternary operator expressions. A contrived example:
$value = ( $a == $b ) ? 'true value # 1' : ( $a == $c ) ? 'true value # 2' : 'false value';
Personally which style you use, or find most readable?
Edit: (on when to use ternary-operator)
I usually avoid using more than 2 levels deep ternary operator. I tend prefer 2 levels deep ternary operator over 2 level if-else, when I’m echoing variables in PHP template scripts.
The ternary operator is generally to be avoided, but this form can be quite readable:
This way, the condition and the result are kept together on the same line, and it’s fairly easy to skim down and understand what’s going on.