zend practice question

PHP Basic:

1. echo 0x8A + 3

2. true ? 0 : true ? 1 : 2;

3. PHP code (or \r, \n, \r\n)

4. echo ~ $x &  $y;

5. echo $x << $y;

6. echo $x >> $y;

7. echo $x ^ $y;

8. (5 % -3) = 2;  (-5 % 3) = -2

9. $a = ($b = 4) + 5;

10. 3 = $a; // output error

11. $a = 3; $b = &$a; $b = 50;print "$a\n"; print "$b\n";

12. $a = &new C;

13. print 0=='a1'? 'TRUE': 'FALSE';

14. 0=='a1'? print 'TRUE': print 'FALSE';

15. NOT 0=='a1'? echo 'TRUE': echo 'FALSE';

16. Execution (backtick) Operators

17. Error Control Operators

18. if ($obj instanceof A)

19. $greeting = <<<"GREETING" She said "That is $name's" dog! GREETING;

20. $greeting = <<<'GREETING' She said "That is $name's" dog! GREETING

21. var_dump(01090); 

22. 0b , 0x

23. 1.234, 1.2e3, 7E-10

24. 000 is TRUE

25. "Hello ".$arr['fruit'];

26. "Hello {$arr['fruit']}"

27. function increment(&$var){ call_user_func();++$var;}
$a = 0;
call_user_func('increment', $a);
echo $a;

28. $a = 'name';
$$a = "Paul";
echo ${'name'}; //Paul

29. function myfunc() { … } $f = 'myfunc'; $f();

30. function SUM() { global $a, $b; return $a + $b; }

31. function SUM() { return $GLOBALS['a'] + $GLOBALS['b']; }

32. function SUM($b) { static $a = 0; $a = $a + $b; return $a; }

33. PHP_EOL

34. switch ($i) {
      case 0: // a semi-colon may be used i.e. case 0;
           case 1:
           case 2:
      echo "i is less than 3 but not negative";
      break;
      case 3:
      echo "i is 3";
   }
   
35. 

for($i=0,$j=50; $i<100; $i++) {
while($j--) {
if($j==17) goto end;
}
}
echo "i = $i";
end:
echo 'j hit 17';

36. 

print 'something'; or print ('something');

die; die(); or exit; exit();

return; // halt the execution and return a value, code after which will NOT run but parsed

__halt_compiler(); // useful for debugging, code after which will not be parsed 

Evaluation Language Constructs

empty(); emptyeval(); require(); or include_once/require_once();
reset()

37. set_error_handler

38. try {    } catch (Exception $e) { echo $e->getMessage(); }

39. difference between $a=’\my\username’;  $a=“\\my\\username”;

40. 
function foo(&$var){
  $var++;
};
$a=5;
foo($a);

41. PECL (PHP Extension Community Library)

42. gc_collect_cycles()

43. 

$a = 1.234; 
$b = 1.2e3; 
$c = 7E-10;

44. 
$x = 8 - 6.4;  // which is equal to 1.6
$y = 1.6;
var_dump($x == $y);

45. 


$strHex = "C45F82ED";

$bin = str_pad(base_convert($strHex, 16, 2), 32, "0", STR_PAD_LEFT);
$sign = $bin[0];
$exp = bindec(substr($bin, 1, 8)) - 127;
$man = (2 << 22) + bindec(substr($bin, 9, 23));

$dec = $man * pow(2, $exp - 23) * ($sign ? -1 : 1);

echo "Answer = " . $dec . "<BR>\n";


46. echo (4.1-floor(4.1));

47. 

$x = 0.23;
$js = "var foo = doBar($x);";
print $js;

48. 

function strrev_x($s, $x = 2) {
    if ($x <= 1) {
        return strrev($s);
    } else {
        return (implode(array_reverse(array_map('implode', array_chunk(str_split($s), $x)))));
    }
}


49. 

$tst = pack('d', '1.6');
var_dump(strrev_x(bin2hex($tst)));
$tst = pack('d', 8-6.4);
var_dump(strrev_x(bin2hex($tst)));
echo 'float pack'. PHP_EOL;
$tst = pack('f', '1.6');
var_dump(strrev_x(bin2hex($tst)));
$tst = pack('f', 8-6.4);
var_dump(strrev_x(bin2hex($tst)));

50. 

function hexTo32Float($strHex) {
    $v = hexdec($strHex);
    $x = ($v & ((1 << 23) - 1)) + (1 << 23) * ($v >> 31 | 1);
    $exp = ($v >> 23 & 0xFF) - 127;
    return $x * pow(2, $exp - 23);
}

echo hexTo32Float("C4028000"); // outputs: -522
echo hexTo32Float("457F9000"); // outputs: 4089
echo hexTo32Float("2D7F5");    // outputs: 6.00804264307E-39
echo hexTo32Float("0002D7F5"); // outputs: 6.00804264307E-39
echo hexTo32Float("47D9F95E"); // outputs: 111602.734375

51. 

$binarydata32 = pack('H*','00000000');
$float32 = unpack("f", $binarydata32); // 0.0

$binarydata64 = pack('H*','0000000000000000');
$float64 = unpack("d", $binarydata64); // 0.0


52. 

for( $tmp = 0, $i = 0; $i < 100; $i++ ) {
    $tmp += 100000;
    echo round($tmp),"\n";
}

53. echo intval(19.31 * 100);


54. 

function hex2float($number) {
    $binfinal = sprintf("%032b",hexdec($number));
    $sign = substr($binfinal, 0, 1);
    $exp = substr($binfinal, 1, 8);
    $mantissa = "1".substr($binfinal, 9);
    $mantissa = str_split($mantissa);
    $exp = bindec($exp)-127;
    $significand=0;
    for ($i = 0; $i < 24; $i++) {
        $significand += (1 / pow(2,$i))*$mantissa[$i];
    }
    return $significand * pow(2,$exp) * ($sign*-2+1);
}

55. 

<?php if ($expression == true): ?>
  This will show if the expression is true.
<?php else: ?>
  Otherwise this will show.
<?php endif; ?>

56. 

<?php
$me =  'Pyornide';
?>
<?=$me;?> is happy.
<?php
$me = strtoupper($me);
?>
<?=$me;?> is happier.

57. 

function long_to_GET(){
    /**
    * This function converts info.php/a/1/b/2/c?d=4 TO
    * Array ( [d] => 4 [a] => 1 [b] => 2 [c] => )
    **/
    if(isset($_SERVER['PATH_INFO']) && $_SERVER['PATH_INFO'] != ''){
        //Split it out.
        $tmp = explode('/',$_SERVER['PATH_INFO']);
        //Remove first empty item
        unset($tmp[0]);
        //Loop through and apend it into the $_GET superglobal.
        for($i=1;$i<=count($tmp);$i+=2){ $_GET[$tmp[$i]] = $tmp[$i+1];}
    }
}


58. 

$_GET['avar'] = 'b';
print_r($_GET); print('<br>');
print_r($_REQUEST);

59. 

var_dump(isset($_ENV['PATH'])); // bool(false)
getenv('PATH');
var_dump(isset($_ENV['PATH'])); // bool(true)


60. 

$a = 1;
$b = 2;

function Sum()
{
    $GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
} 

Sum();
echo $b;

61. 

static $int = 0;          // correct 
static $int = 1+2;        // correct (as of PHP 5.6)
static $int = sqrt(121);  // wrong  (as it is a function)

$int++;
echo $int;
    
62. 

for($j=0; $j<3; $j++)
{
     if($j == 1)
        $a = 4;
}
echo $a;


63. 

function foo ()
{
   global $testvar;

   $localvar = new Object ();
   $testvar = &$localvar;
}

foo ();
print_r ($testvar); 


64.

if (isset($_COOKIE['count'])) {
    $count = $_COOKIE['count'] + 1;
} else {
    $count = 1;
}
setcookie('count', $count, time()+3600);
setcookie("Cart[$count]", $item, time()+3600);


65.

function multi_post_item($input_item_name) {
     $array_output = array();
     $in_handle = fopen("php://input", "r");
     $raw_input_items = split("&", urldecode(fread($in_handle, 100000)));
     foreach ($raw_input_items as $input_item) {
            // split this item into name/value pair
            $item = split("=", $input_item);
            // form item name
            $item_name = $item[0];
            // form item value
            $item_value = $item[1];
            if ($item_name == $input_item_name) {
                    $array_output[] = $item_value;
            }
     }
     return $array_output;
}


66. 

echo "$a ${$a}";

67.

  $Bar = "a";
  $Foo = "Bar";
  $World = "Foo";
  $Hello = "World";
  $a = "Hello";

  $a; //Returns Hello
  $$a; //Returns World
  $$$a; //Returns Foo
  $$$$a; //Returns Bar
  $$$$$a; //Returns a

  $$$$$$a; //Returns Hello
  $$$$$$$a; //Returns World
  
  
68. 
    
$tab = array("one", "two", "three") ;
$a = "tab" ;
${$a}[] =  "four" ; // <==== this is the correct way to do it
print_r($tab) ;

69.

${date("M")} = "Worked";
echo ${date("M")};

70.

namespace MyNamespace;

class Foo
{
    public function __construct()
    {
        echo "I'm a real class!" . PHP_EOL;
    }
}

$class = 'MyNamespace\Foo';

$instance = new $class;

71.

class pp{
   var $prop1=1,$prop2=2,$prop3=array(3,4,5);

   function fun1(){
      $vars=get_class_vars('pp');
      while(list($var,$value)=each($vars)){
               $ref=& $this->$var;
               $ref=$_GET[$var];

      } // while
      var_dump($this);
   }
}

$_GET['prop1']="uno";
$_GET['prop2']="dos";
$_GET['prop3']=array('tres','cuatro','cinco','seis');

$p=new pp();
$p->fun1();

72. 

$p1=microtime(true);
$x=0;
for($i=0;$i<50000000;$i++) {
    $x+=CNS;
}
$p2=microtime(true);


73. 

define('echo', 'My constant value');

echo constant('echo'); // outputs 'My constant value'

74.

function double($i)
{
    return $i*2;
}
$b = $a = 5;        /* assign the value five into the variable $a and $b */
$c = $a++;          /* post-increment, assign original value of $a 
                       (5) to $c */
$e = $d = ++$b;     /* pre-increment, assign the incremented value of 
                       $b (6) to $d and $e */

/* at this point, both $d and $e are equal to 6 */

$f = double($d++);  /* assign twice the value of $d before
                       the increment, 2*6 = 12 to $f */
$g = double(++$e);  /* assign twice the value of $e after
                       the increment, 2*7 = 14 to $g */
$h = $g += 10;      /* first, $g is incremented by 10 and ends with the 
                       value of 24. the value of the assignment (24) is 
                       then assigned into $h, and $h ends with the value 
                       of 24 as well. */
                       
                       
75.

$a = 2, $b = 4;

echo $a."\n";
echo $b."\n";


Example (works):

for ($a = 2, $b = 4; $a < 3; $a++)
{
  echo $a."\n";
  echo $b."\n";
}


76. 

$n = 3;
$n * --$n

77. 

function a() {echo 'a';}
function b() {echo 'b';}
a() == b(); // outputs "ab", ie evaluates left-to-right

$a = 3;
var_dump( $a == $a = 4 ); 

78.

print array() == NULL ? "True" : "False";
print " (" . (array() == NULL) . ")\n";

$arr = array();
print array() == $arr ? "True" : "False";
print " (" . (array() == $arr) . ")\n";

print count(array()) . "\n";
print count(NULL) . "\n";


79.

$a = 2;

echo ($a == 1 ? 'one' :
        ($a == 2 ? 'two' :
        ($a == 3 ? 'three' :
        ($a == 4 ? 'four' : 'other') ) ) );
echo "\n";

80.