BlueShoes: PHP Syntax Exam

Do you know what empty(false) evaluates to? or empty('0')? How about ('-1' == true)? Well see yourself :-)

This test was created based on php 4.0.5, and is updated for php 4.2.2. All this has been proofed on Win2k using PHP 4.2.2 using the PhpUnit test class "PhpSyntax_PhpUnit.class.php". It is included in the download package. Once you're done you might want to check the PHP Cheat Sheet.

The following vars are set:


  var $empty       = '';
  var $null        = NULL;
  var $bool        = FALSE;
  var $notSet;
  var $array       = array();

empty (var $empty = "";)

1.	datatype of `$empty`?

2.	`$x = empty($empty);` what is `$x`? true false

3.	`$x = is_null($empty);` what is `$x`? true false

4.	`$x = isSet($empty);` what is `$x`? true false

5.	`$x = (bool)$empty;` what is `$x`? true false

null (var $null = NULL;)

6.	datatype of `$null`?

7.	`$x = empty($null);` what is `$x`? true false

8.	`$x = is_null($null);` what is `$x`? true false

9.	`$x = isSet($null);` what is `$x`? true false

10.	`$x = (bool)$null;` what is `$x`? true false

notSet (var $notSet;)

11.	datatype of `$notSet`?

12.	`$x = empty($notSet);` what is `$x`? true false

13.	`$x = is_null($notSet);` what is `$x`? true false

14.	`$x = isSet($notSet);` what is `$x`? true false

15.	`$x = (bool)$notSet;` what is `$x`? true false

array (var $array = array();)

16.	`$x = empty($array);` what is `$x`? true false

17.	`$x = is_null($array);` what is `$x`? true false

18.	`$x = isSet($array);` what is `$x`? true false

19.	`$x = (bool)$array;` what is `$x`? true false

20.	`$x = (array('foo') == array('foo'));` what is `$x`? true false

21.	`$x = (array('a'=>'foo') == array('b'=>'foo'));` what is `$x`? true false

22.	`$arrOne = array(''=>''); $arrTwo = array('9'=>'apple', '15'=>'banana', '20'=>'grapefruit'); $x = array_merge($arrOne, $arrTwo);` what is `$x`? 1) array(''=>'', 0=>'apple', 1=>'banana', 2=>'grapefruit'); 2) array(''=>'', 9=>'apple', 15=>'banana', 20=>'grapefruit');

bool (var $bool = FALSE;)

23.	`$x = empty($bool);` what is `$x`? true false

24.	`$x = is_null($bool);` what is `$x`? true false

25.	`$x = isSet($bool);` what is `$x`? true false

compare

26.	`$x = (bool)($empty == $null);` what is `$x`? true false

27.	`$x = (bool)($empty == $notSet);` what is `$x`? true false

28.	`$x = (bool)($null == $notSet);` what is `$x`? true false

29.	`$x = (bool)($empty === $null);` what is `$x`? true false

30.	`$x = (bool)($empty === $notSet);` what is `$x`? true false

31.	`$x = (bool)($null === $notSet);` what is `$x`? true false

string

32.	`$x = (bool)("hello");` what is `$x`? true false

33.	`$x = (bool)("15");` what is `$x`? true false

34.	`$x = (bool)("0");` what is `$x`? true false

35.	`$x = (bool)("-1");` what is `$x`? true false

36.	`$x = (bool)("true");` what is `$x`? true false

37.	`$x = (bool)("false");` what is `$x`? true false

number

38.	`$x = (bool)(15);` what is `$x`? true false

39.	`$x = (bool)(1);` what is `$x`? true false

40.	`$x = (bool)(0);` what is `$x`? true false

41.	`$x = (bool)(-1);` what is `$x`? true false

compare 2

42.	`$x = (bool)("15" == 15);` what is `$x`? true false

43.	`$x = (bool)("15" === 15);` what is `$x`? true false

44.	`$x = (bool)("hello" == 15);` what is `$x`? true false

45.	`$x = (bool)("hello" === 15);` what is `$x`? true false

46.	`$x = (bool)("hello" == "true");` what is `$x`? true false

47.	`$x = (bool)("hello" === "true");` what is `$x`? true false

48.	`$x = (bool)("hello" == 1);` what is `$x`? true false

49.	`$x = (bool)("hello" === 1);` what is `$x`? true false

50.	`$x = (bool)("hello" == TRUE);` what is `$x`? true false

51.	`$x = (bool)("hello" === TRUE);` what is `$x`? true false

datatype

52.	`$x = (TRUE);` datatype of `$x`?

53.	`$x = ("15" == 15);` datatype of `$x`?

54.	`$x = ((TRUE) && (TRUE));` datatype of `$x`?

55.	`$x = ((TRUE) AND (TRUE));` datatype of `$x`?

56.	`$x = ((TRUE) \|\| (TRUE));` datatype of `$x`?

57.	`$x = ((TRUE) OR (TRUE));` datatype of `$x`?

reference

58.	`$a = "hello"; $b = &$a; $b = "world";` what is `$a`?

59.	`$a = "hello"; $b = &$a; unset($b); $b = "world";` what is `$a`?

60.	`$a = "hello"; $b = &$a; unset($b);` what is `$a`?

61.	`$a = "hello"; $b = &$a; $b = "world"; unset($b);` what is `$a`?

pre post de increment

62.	`$a = 1; $b = $a++;` what is `$b`?

63.	`$a = 1; $b = ++$a;` what is `$b`?

pre post de increment (with reference)

64.	`$a = 1; $x = &$a; $b = $a++;` what is `$b`?

65.	`$a = 1; $x = &$a; $b = ++$a;` what is `$b`?

hash keys

66.	`$a = 'foo'; $b = isSet($a['bar']);` what is `$b`? true false

67.	`$a = 'foo'; $b = empty($a['bar']);` what is `$b`? true false

68.	`$a = array('foo'=>'foo'); $b = isSet($a['bar']);` what is `$b`? true false

69.	`$a = 1; $b = isSet($a['bar']);` what is `$b`? true false

good luck :)