note 123038 deleted from language.operators.comparison by cmb

Note Submitter: phpnotes at zavaboy dot com ---- A note on null coalescing operators with arithmetic as it may not be obvious for some people. <?php // Only $a and $c are defined as: $a = 4; $c = 2; // When you do this: echo $a ?? 0 + $b ?? 0 + $c ?? 0 ; // 4 // You may have expected a result like this: echo ($a ?? 0)+($b ?? 0)+($c ?? 0); // 6 // But this is basically what's going on: echo $a ??(0 + $b)??(0 + $c)?? 0 ; // 4 ?> Also note the first and last will produce an E_NOTICE if $a is not defined or null and $b is not defined: Notice: Undefined variable: b in __FILE__ on line __LINE__ See also: http://php.net/manual/en/language.operators.precedence.php