I\'ve perused the questions on ternary operators vs. if/else structures, and while I understand that under normal circumstances there is no performance los
I don't know if your first example is inefficient, but it sure is pointless. I still think an if statement is clearer:
$foo = 'bar';
if (strlen($foo) > 3)
$foo = substr($foo, 0, 3);
And while the following works, it makes no sense to place null at the end because a ternary operator is meant to be used to evaluate expressions/values, but here null does nothing other than to prevent a parse error:
!defined('SECURE') ? exit : null;
More commonly, you would see this, an example of boolean short-circuiting (or exit doesn't execute if SECURE is defined, because the or conditional expression evaluates to true automatically once at least one condition is found to be true):
defined('SECURE') or exit;
The point I'm trying to make is this: don't use ternary conditional expressions just because you can.