note 104675 added to language.types.array

//unexpected behavior when passing pre-defined arrays with null elements to a function... function do_something_with_an_array( $ARRAY ) { return $ARRAY; } //a word of warning... $ARRAY = array( 'key1'=> 'val1', 'key2'=>null, 'key3'=> 'val3' ); $result = do_something_with_an_array( $ARRAY ); print_r( $result ); --- output: --------- array ( 'key1' => 'val1', 'key3' => 'val3' ) --------------------- //is not the same as... $result = do_something_with_an_array( array( 'key1'=> 'val1', 'key2'=>null, 'key3'=> 'val3' ) ); print_r( $result ); --- output: --------- array ( 'key1' => 'val1', 'key2' => null, 'key3' => 'val3', ) --------------------- //the difference is the first will DROP the null element from the array before the function gets it where the second will PRESERVE the array structure //why is this important? I use a function like this to serialize the $_GET to a url query string... the $ARRAY I pass contains the changes to make to the values, I often use this to remove elements by merging the $_GET & $ARRAY with null value elements in the $ARRAY //if these elements are destroyed in passing the arguments then I cannot remove an argument from the url //why don't I just unset($_GET['key2']) ? because I want to preserve the $_GET for use further in the code ---- Server IP: 69.147.83.197 Probable Submitter: 67.0.0.130 ---- Manual Page -- http://www.php.net/manual/en/language.types.array.php Edit -- https://master.php.net/note/edit/104675 Del: integrated -- https://master.php.net/note/delete/104675/integrated Del: useless -- https://master.php.net/note/delete/104675/useless Del: bad code -- https://master.php.net/note/delete/104675/bad+code Del: spam -- https://master.php.net/note/delete/104675/spam Del: non-english -- https://master.php.net/note/delete/104675/non-english Del: in docs -- https://master.php.net/note/delete/104675/in+docs Del: other reasons-- https://master.php.net/note/delete/104675 Reject -- https://master.php.net/note/reject/104675 Search -- https://master.php.net/manage/user-notes.php