PHP學習之文法基礎篇

<?#asp風格短標記  echo "hello world!<br/>";?><?php   $date = "2013-5-21";?><p>today's date is <?php echo $date;?></p><?php   print("<br/>print test!");  $name = "zhangsan";  $age = 20;  printf("<br/>name:%s,age:%d",$name,$age);    $str = sprintf("<br/>hello...<br/>");  echo $str;   $a = true;  $lst["aa"] = "aaaaa";  $lst["bb"] = "bbbb";  $lst["cc"] = "cccc";    var_dump($lst);  print_r($lst);    $k = (int)10.8; #強制類型轉換  print("<br/>".$k);    #類型轉換  $i = "123";  echo "<br/>i的類型為:".gettype($i);  settype($i, integer);  echo "<br/>轉換後i的類型為:".gettype($i);      $t = "ssss";  function checkType($obj){       if(is_integer($obj)){           echo "<br/>傳遞的類型為int";       }elseif (is_bool($obj)){           echo "<br/>傳遞的類型為bool";       }elseif (is_string($obj)){           echo "<br/>傳遞的類型為string";       }else{           echo "<br/>未知類型...";       }  }    checkType("100000");  checkType(200);  checkType(false);    #引用賦值  $y = "hahaha";  #$z = $y;  $r = &$y;  #$z = "hhhhh";  $r = "uuuu";    echo "<br/>$y";     #傳引用  function refTest(&$kk){      $kk = 2 * $kk;  }    $dd = 100;  refTest($dd);  echo "<br/>".$dd;    #傳值  function valTest($kk){      $kk = 5 * $kk;  }    $k1 = 500;  valTest($k1);  echo "<br/>".$k1;      #變數範圍  #局部變數與全域變數    $t2 = 1200; #全域變數  function changeNumber(){     $t2 = 1500;#局部變數  }   changeNumber();  echo "<br/>$t2"; #列印1200    function changeNumber1(){      global $t2;      #global $t2 = 1800; error      $t2 = 1800;  }    changeNumber1();  echo "<br/>$t2"; #列印1800      function Test()  {    $GLOBALS["txn"] = 500; #$GLOBALS 必須大寫  }  Test();  echo "<br/>".$GLOBALS["txn"];      #靜態變數  function keep_trace(){      static $count = 0;      $count++;      echo "$count<br/>";  }    keep_trace();  keep_trace();  keep_trace();  keep_trace();      #超級全域變數  foreach($_SERVER as $k => $v){      print("$k => $v<br/>");  }    #$_GET  if(isset($_GET["name"])){      printf("目前使用者:%s",$_GET["name"]);  }  #$_POST  if(isset($_POST["name"])){      printf("目前使用者:%s",$_POST["name"]);  }    #cookie  setcookie("domain","my.com");  if(isset($_COOKIE["domain"])){      printf("當前域資訊:%s<br/>",$_COOKIE["domain"]);  }    #files  #$_FILES["file"]["name"];  #$_FILES["file"]["type"];  #$_FILES["file"]["size"];  #$_FILES["file"]["error"];    #seession  $_SESSION["user"] = "wangwu";  echo "當前操作人：".$_SESSION["user"]."<br/>";    #常量的定義  define("PI",3.1415926);  $pi2 = PI * 2;  echo "2pi:$pi2<br/>";  ?>