--TEST-- Test array_change_key_case() function : usage variations - different data types as keys --FILE-- array( 0 => 'zero', 1 => 'one', 12345 => 'positive', -2345 => 'negative', ), // float data /*2*/ 'float' => array( 10.5 => 'positive', -10.5 => 'negative', .5 => 'half', ), 'extreme floats' => array( 12.3456789000e6 => 'large', 12.3456789000E-10 => 'small', ), // null data /*3*/ 'null uppercase' => array( NULL => 'null 1', ), 'null lowercase' => array( null => 'null 2', ), // boolean data /*4*/ 'bool lowercase' => array( true => 'lowert', false => 'lowerf', ), 'bool uppercase' => array( TRUE => 'uppert', FALSE => 'upperf', ), // empty data /*5*/ 'empty double quotes' => array( "" => 'emptyd', ), 'empty single quotes' => array( '' => 'emptys', ), // string data /*6*/ 'string' => array( "stringd" => 'stringd', 'strings' => 'strings', $heredoc => 'stringh', ), // undefined data /*8*/ 'undefined' => array( @$undefined_var => 'undefined', ), // unset data /*9*/ 'unset' => array( @$unset_var => 'unset', ), ); // loop through each sub-array of $inputs to check the behavior of array_change_key_case() $iterator = 1; foreach($inputs as $key => $input) { echo "\n-- Iteration $iterator : $key data --\n"; var_dump( array_change_key_case($input, CASE_UPPER) ); $iterator++; }; echo "Done"; ?> --EXPECT-- *** Testing array_change_key_case() : usage variations *** -- Iteration 1 : int data -- array(4) { [0]=> string(4) "zero" [1]=> string(3) "one" [12345]=> string(8) "positive" [-2345]=> string(8) "negative" } -- Iteration 2 : float data -- array(3) { [10]=> string(8) "positive" [-10]=> string(8) "negative" [0]=> string(4) "half" } -- Iteration 3 : extreme floats data -- array(2) { [12345678]=> string(5) "large" [0]=> string(5) "small" } -- Iteration 4 : null uppercase data -- array(1) { [""]=> string(6) "null 1" } -- Iteration 5 : null lowercase data -- array(1) { [""]=> string(6) "null 2" } -- Iteration 6 : bool lowercase data -- array(2) { [1]=> string(6) "lowert" [0]=> string(6) "lowerf" } -- Iteration 7 : bool uppercase data -- array(2) { [1]=> string(6) "uppert" [0]=> string(6) "upperf" } -- Iteration 8 : empty double quotes data -- array(1) { [""]=> string(6) "emptyd" } -- Iteration 9 : empty single quotes data -- array(1) { [""]=> string(6) "emptys" } -- Iteration 10 : string data -- array(3) { ["STRINGD"]=> string(7) "stringd" ["STRINGS"]=> string(7) "strings" ["HELLO WORLD"]=> string(7) "stringh" } -- Iteration 11 : undefined data -- array(1) { [""]=> string(9) "undefined" } -- Iteration 12 : unset data -- array(1) { [""]=> string(5) "unset" } Done