 2                ,        .       :  ;  ; ; ; ;  .           .     ,     ( ).        .                  .   :  5  591  52               (  8)   (  16)  .      0,       0  7. :  0422  0534       0  0       0  9     ()  f (F). :  0x3FF  0x22abc       (   )      .     ,   ,  ,    .      :    () .              ,  . :  12.45  98.6                  ,     . :  8  5.973624      (string)   ,     ,        .  :  thesaurus  49ers  abc  &%/$#   :       .         ,      .                     (" ")   (' ').       . -,    ,   ,   ,      ,       ,       :  $food = "meatloaf";  $food = 'meatloaf';       :  $sentence = "My favorite food is $food";  $sentence2 = 'My favorite food is $food';   $sentence    My favorite food is meatloaf.   :  $food  .   ,  $sentence2    My favorite food is $food.      $sentence,  $sentence2     $food.          $sentence  $sentence2.         ,      ,     ,    .  ,       ,      (,     ),   . 2.1.   2.1.      	    \n	 	
 \r	 	
 \t	 	 \\	  	
 \$	 	 \"		 \[0-7]{1,3}	   (   )	
 \x[0-9A-Fa-f]{l,2}	   (   )	       ,   ,   ,     ,   ,   ,     \\  \.        ,     :  $double_list = "item1\nitem2\nitem2";  $single_list = 'item1\nitem2\nitem2';       , ,         ,       \n    .       ,          .   ,     ,      .          ,   HTML4,    (here doc).         <<<,        ,  ,  .       . :  $paragraph = <<<DELIM  This is a string that  Will be interpreted exactly  As it is written in the  variable assignment,  DELIM;         .  ,          ,  .                     (.  ). :  $sequence_number = "04efgh";  $letter = Ssequence_number[4];   $ letter    g.      ,        0. ,  $sequence_number[l]   4.         .    ,     .         .      ,       ,    . ,          .        .               ,    .      :  $[1];      :  $meat[0] = "chicken";  $meat[l] = "steak";  $meat[2] = "turkey";     :  print $meat[1]:       steak         array ().  $meat       $meat = rr("chicken", "steak", "turkey");     pri nt         steak.        ,         . ,  $meat     :  Smeat[] = "chicken";  $meat[] = "steak";  Smeat[] = "turkey";           ,       ,    .  ,          .         /  ,     .       :  Spairings["zinfandel"] = "Broiled Veal Chops";  $pairings["merlot"] = "Baked Ham";  $pairings["sauvignon"] = "Prime Rib";  $pairings["sauternes"] = "Roasted Salmon";          ,      . ,   ,       .         $pairings: print $pairings["merlot"]; //   "Baked Ham"        ():  Spairings = rr(  zinfandel => "Broiled Veal Chops",  merlot => "Baked Ham",  sauvignon => "Prime Rib",  sauternes => "Roasted Salmon");       pairings,      .            ,     ,         .      ,            3.      :  $[1][2]..[N];        :  $position = $chess_board[5][4];             (   ). ,   $irings          ,     .     :  $pairings["Martinelli"]["zinfandel"] = "Broiled Veal Chops";  $pairings["Beringer"]["merlot"] = "Baked Ham";  $pairings["Jarvis"]["sauvignon"] = "Prime Rib";  $pairings["Climens"]["sauternes"] = "Roasted Salmon";           (  ). ,                  .     :  $Buckeyes["quarterback"] [1] = "Bellisari";  $Buckeyes["quarterback"] [2] = "Moherman":  $Buckeyes["quarterback"] [3] = "Wiley";                  ,    .          13.          .    ,      ,  .         -  ().       ,    ,    .  ,        ,             . ,      ,    .          :  class appliance {   var power:   function set_power($on_off) {   $this->power = $on_off;   }   }  ...  $blender = new appliance;        ,              appliance ().        power ().       set_power.  :      ,        ;        .       new. ,       $blender  appliance.     $blender         set_power: $blender->set_power("on");  -         ,        .        6.    (/)        :  (true)   (false).     :        .    .      .        =    if. :  if ($sum == 40) :  ...      ,  :  $sum   40,   .   $sum  40,    .      false.             . :  $flag = TRUE;  if ($flag == TRUE) :  print "The flag is true!";  else :  print "The flag is false!";  endif;    $flag ,   ,      .                1  0 .       :  $flag = 1;  if ($flag == TRUE) ;  print "The flag is true!";  else :  print "The flag is false!";  endif;  ,    :  $flag = TRUE:   //        //   "if ($flag == TRUE)"   if ($flag) :  print "The flag is true!";   else :  print "The flag is false!";   endif:         ,    ,  .      :               .     , ,     ASCII-    127  255. :  	     my_function  This&that Size	!counter	 _someword	4ward	      . ,    $recipe      $Recipe, $rEciPe  $recipE.     .  ,          .       -     .     ,  ,   ,       .              .      .          ,  ,         .        , $.      :  $lr  $operating_system  $_some_variable  $model        ,   .  ,            ,  ,    ASCII-    127  255.   ,    ,     Perl,    .          .  ,          .   :  $sentence = "This is a sentence."; // $sentence     $price = 42.99: // $price      $weight = 185; // $weight             ,      ,      .        (scope)        ,     .           :
  ;  ;  ;  .     ,   ,  ;  ,        .          ,      ( )  ,   .    ,      ,      .          ,        .   :  $ = 4;   function assignx () {   $ = 0;  print "\$x inside function is $x. <br>";  }  assignx();   print "\$x outside of function is $x. <br>";        :   $ inside function is 0.   $ outside of function is 4.    ,       $.   ,   $   assignx   ,         ,     .      $           assignx().      ,       ,  ,    ,      .    ,  ,       .         .         :  //      10     function x10 ($value) {  $value = $value * 10;  return $value;  }          ,     ,      ,     .      ,    ,     .      ,         .         GLOBAL. :  $somevar = 15;  function addit() {   GLOBAL $somevar;   $somevar++;   print "Somevar is $somevar";   }   addit();      $somevar,  16. ,     :  GLOBAL $somevar;     $somevar    1,           addit( ).      0,      1;  ,    1.            $GLOBALS( ).              $somevar: $somevar = 15;  function addit() {   $GLOBALS["somevar"];   $somevar++;   }  addit();  print "Somevar is $somevar";         , ,          ,    .  ,     ,     .          .    ,        ,        .           STATIC:   STATIC $somevar;    :   function keep_track() {   STATIC $count = 0;   $count++;  print $count;  print "<br>";  }   keep_track();   keep_track();   keep_track();         ?    $count     (   ),    :  1   1   1      $count  ,         ,    :  1   2  3             ,         .      4.          ,     . ,      "15"    12.  ,           .  ,   ,      ,   (juggling) .       .  ,         .   ,    ?     . ,            :  $variablel = 1;  $variable2 = "1";  $variable3 = $variablel + $variable2;  // $variable3  4.           .        ,    :  $variablel = 3;  $variable2 = 5.4;  $variable3 = $variablel + $variable2;  // $variablel    .  //  $variable3  8.4.         .         ,   ,     ?   :  $variablel = 5;  $variable2 = "100 bottles of beer on the wall";  $variable3 = ;variable1 + $variable2;  // $variable3  105     ;variable3   105.   - ,         . ,    $variable2   "There are 100 bottles of beer on the wall".        ,    0,   $variable3  5.          ,        .      .         ,   ,     ,   (casting) .      , ,   .        ,                (. 2.2).   2.2.       	 	
 (int)  (integer)	 	 (real), (double)  (float)	 	 (string)		 (array)		 (object)		     :   $variable1= 13; // $variable1    13  $variable2 = (double) $variable1; // $variable2  13.0    $variable1     13,  (double)      (  13   13.0).     $variable2.      ,          .         :  $variablel = 4.0;  $variable2 = 5;  $variable3 = (int) $variable1 + $variable2; // $variable3 = 9   ,         :  $variablel = 14.7:  $variable2 = (int) $varlable1; // $variable2 = 14:            .         :  $variable1 = 1114;  $array1 = (array) $varable1;  print $array1[0]; //   1114  ,       .    ,     scalar:  $model = "Toyota";  $new_obj = (object) $model;        :  print $new_obj->scalar;      ,       .   ,  ,   ,   . ,       ,         ,   1   "ciao".         ,       .        .          ,        ,   .    :  $vehicle = "car";   $amount =10.23;           ,   $vehicle,   "car",   ,   $amount,   10.23.            return  :  function simple () {  return 5;  }  $return_value = simple();   simple( )     5,    .     5    $return_value.                ,   .    -    ( )   ,     .      ,    -  & ():  $dessert = "cake";  $dessert2 = $Sdessert;  $dessert2 = "cookies";  print "$dessert2 <br>"; //   cookies  print Sdessert; //    cookies      ,    $dessert2     ,   $dessert,   $dessert2     $dessert (   ,      ).            ,         .    :  $recipe = "spaghetti";  ,  "spaghetti"                   $:  $$recipe = "& meatballs";      "& meatballs"    "spaghetti". ,      :  print $recipe $spaghetti;  print $recipe $($recipe);        "spaghetti & meatballs".          ,          .     ,         web-,    .              ,      .       web-,   ,     ,    :  while (list($var,$value) = each($GLOBALS)) :  echo "<BR>$var => $value";  endwhile;        .       ,     .  GLOBALS =>  HTTP_GET_VARS => Array   HTTP_COOKIE_VARS => Array   HOSTSIZE => 1000   HOSTNAME => server1.apress.com   LOGNAME => unstrung   HISTFILESIZE => 1000   REMOTEHOST => apress.com   MAIL -> /var/spool/mail/apress   MACHTYPE => 1386   TERM => vt100   HOSTTYPE => i386-linux   PATH =>   /usr/sbin:/sbin:/usr/local /bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/Java/bin   HOME => /root   INPUTRC => /etc/inputrc   SHELL => /bin/csh   USER => nobody   VENDOR => intel   GROUP => root   HOST => server1.apress.com   OSTYPE => linux   PWD => /www/bin   SHLVL => 3_ => /www/bin/httpd   DOCUMENT_ROOT => /usr/local/apress/site.apress   HTTP_ACCEPT => */*   HTTP_ACCEPT_ENCODING => gzip, deflate   HTTP_ACCEPT_LANGUAGE => it.en-us;q=0.5   HTTP_CONNECTION -> Keep-Alive   HTTP_HOST => www.apress.com   HTTP_USER_AGENT => Mozilla/4.0 (compatible; MSIE 5.0: Windows 98;   CNETHomeBuild051099)   REMOTE_ADOR => 127.0.0.1   REMQTE_PORT => 3207   SCRIPT_FILENAME => /usr/local/apress/site.apress/j/environment_vars.php   SERVER_ADDR => 127.0.0.1   SERVER_AOMIN => admin@apress.com   SERVER_NAME => www.apress.com   SERVERJORT => 80   SERVER SIGNATURE =>   Apache/1.3.12 Server at www.apress.com Port 80   SERVER_SOFTWARE => Apache/1.3.12 (Unix) PHP/4.0.1   GATEWAY_INTERFACE => CGI/1.1   SERVER_PROTOCOL => HTTP/1.1   REQUEST_METHOD => GET   QUERY_STRING =>   REQUEST_URI => /j/environment_vars.php   SCRIPT_NAME => /j/environment_vars.php   PATH_TRANSLAETD => /usr/local/apress/site.apress/j/environment_vars.php   PHP_SELF => /j/environment_vars.php   argv => Array   argc => 0   var => argc   value => argc    ,        ,    .         . ,    IP- :  print "Hi! Your IP address is: $REMOTE_ADDR";  IP-     (, 208.247.106.187).   ,             .   print "Your browser is: $HTTP_USER_AGENT";     :  Your browser is: Mozina/4.0 (compatible: MSIE 5.0; Windows 98: CNETHomeBuild051099)       ,    ,     ,      .           track_vars   php.ini.    4.0.3  track_vars  .       ,       .           ,  ? (3,141592)      (5280).       define( ).      ,     ( )    .  ,         :  define("'PI", "3.141592");        :  print "The value of pi is". PI."<br>";  $pi2 - 2 * PI:  print "Pi doubled equals $pi2.";       :  The value of pi is 3.141592.  Pi doubled equals 6.283184.          . -,       . -,    (,    2*I);     ,       .           ,          .  ,    :    (   , , , ,  ); ;  (,  );  ;  ;    ( ,  ); .          .         ,      .    3      ,        .