note 125239 added to functions.arrow

Beware compact() not being able to access (import) variables from external scope (known in versions: 7.4.0, 7.4.8) (bug: https://bugs.php.net/bug.php?id=78970). A workaround is available - use the variable directly; this will cause it to be imported into the arrow function's namespace and make it available to the compact() too. <?php $aa = 111; $accessing_variable_works = fn($bb) => [ $aa, $bb ]; $compact_is_broken = fn($bb) => compact('aa', 'bb'); $compact_can_work_with_workaround = fn($bb) => compact('aa', 'bb') + ['workaround' => $aa]; var_dump($accessing_variable_works(333)); var_dump($compact_is_broken(555)); var_dump($compact_can_work_with_workaround(777)); ?> result: array(2) { [0]=> int(111) [1]=> int(333) } PHP Notice: compact(): Undefined variable: aa in /home/m/vlt/guitar/tlb/s/public_html/index.php on line 9 array(1) { ["bb"]=> int(555) } array(3) { ["aa"]=> int(111) ["bb"]=> int(777) ["workaround"]=> int(111) } ---- Server IP: 45.112.84.4 Probable Submitter: 103.51.166.36 (proxied: 188.47.75.214) ---- Manual Page -- http://php.net/manual/en/functions.arrow.php Edit -- https://master.php.net/note/edit/125239 Del: integrated -- https://master.php.net/note/delete/125239/integrated Del: useless -- https://master.php.net/note/delete/125239/useless Del: bad code -- https://master.php.net/note/delete/125239/bad+code Del: spam -- https://master.php.net/note/delete/125239/spam Del: non-english -- https://master.php.net/note/delete/125239/non-english Del: in docs -- https://master.php.net/note/delete/125239/in+docs Del: other reasons-- https://master.php.net/note/delete/125239 Reject -- https://master.php.net/note/reject/125239 Search -- https://master.php.net/manage/user-notes.php