Editing Ternary conditional operator (section)

===PHP===
A simple [[PHP]] implementation is this:

<syntaxhighlight lang="php">
$abs = $value >= 0 ? $value : -$value;
</syntaxhighlight>

Unlike most other programming languages, the conditional operator in [[PHP]] is [[operator associativity|left associative]] rather than right associative. Thus, given a value of '''T''' for '''arg''', the PHP code in the following example would yield the value '''horse''' instead of '''train''' as one might expect:<ref>{{cite web |url=http://eev.ee/blog/2012/04/09/php-a-fractal-of-bad-design/#operators |title=PHP: a fractal of bad design |access-date=2015-10-04 |author=Eevee |date=2012-04-09 }}</ref>

<syntaxhighlight lang="php">
<?php
$arg = "T";
$vehicle = ( ( $arg == 'B' ) ? 'bus' : 
             ( $arg == 'A' ) ? 'airplane' : 
             ( $arg == 'T' ) ? 'train' : 
             ( $arg == 'C' ) ? 'car' : 
             ( $arg == 'H' ) ? 'horse' : 
                               'feet' );
echo $vehicle;
</syntaxhighlight>

The reason is that nesting two conditional operators produces an oversized condition with the last two options as its branches: {{code|c1 ? o1 : c2 ? o2 : o3}} is really {{code|((c1 ? o1 : c2) ? o2 : o3)}}. This is acknowledged<ref>{{cite web |url=http://php.net/ternary#example-121 |title=Comparison Operators, Example #3: Non-obvious Ternary Behaviour |publisher=PHP website |access-date=2013-04-26}}</ref> and will probably not change.<ref>{{cite web |url=https://bugs.php.net/bug.php?id=61915 |title=PHP Bug #61915: incorrect associativity of ternary operator |quote=We can't fix this without breaking code |date=2012-05-02 |access-date=2013-04-26 |publisher=PHP website}}</ref> To avoid this, nested parenthesis are needed, as in this example:

<syntaxhighlight lang="php">
<?php
$arg = "T";
$vehicle = $arg == "B" ? "bus" :
          ($arg == "A" ? "airplane" :
          ($arg == "T" ? "train" :
          ($arg == "C" ? "car" :
          ($arg == "H" ? "horse" :
                         "feet"))));
echo $vehicle;
</syntaxhighlight>

This will produce the result of '''train''' being printed to the output, analogous to a right associative conditional operator.