Multiple conditions in the ternary operator safe?

Question

I have seen advice that says the ternary operator must not be nested.

I have tested the code below and it works okay. My question is, I haven't seen the ternary operator used like this before. So, is this as reliable as it were used in an if or could something like this come and bite me later(not in terms or readability, but by failing).

$rule1 = true;
$rule2 = false;
$rule3 = true;

$res = (($rule1 == true) && ($rule2 == false) && ($rule3 == true)) ? true : false;

if($res) {
    echo "good";        
} else {
    echo "fail";
}

Thanks!

Answer 1

If the results you are returning from the ternary operator are only "true" and "false", then you don't even need the operator. You can just have:

$res = (($rule1 === true) && ($rule2 === false) && ($rule3 === true))

But, to answer your question, yes multiple conditions work perfectly well.

Answer 2

It's totally legal, it works and is "as reliable as if", but it looks ugly.

If you put each ternary statement inside parenthesis, nesting would be fine too:

$res = ( $rule1 ? true : ( $rule2 ? true : false ) )

The only thing that is advised against in the manual is nesting without parenthesis like this:

$res = ( $rule1 ? true : $rule2 ? true : false )