PHP/Data Type/Data Type

Материал из Web эксперт
Версия от 07:03, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

Create Object and check its type

<?php
  class employee {
      var $emp_code;
      var $name;
      var $address;
      var $department;
      var $sex;
      var $date_of_birth;
      var $salary;
  }
  $dave = new employee;
  $alice = new employee;
  echo(is_object($dave)); 
  ?>



Create Object and get its type

<?php
  class employee {
      var $emp_code;
      var $name;
      var $address;
      var $department;
      var $sex;
      var $date_of_birth;
      var $salary;
  }
  $dave = new employee;
  $alice = new employee;
  echo gettype ($dave)," \n";
  echo gettype ($alice), " \n";
  ?>



gettype() and settype() Data Types

Data Type                Returned by gettype                     Set by settype
----------------------------------------------------------------------------------
Array                    Array                                   Array
Boolean                  Boolean                                 Boolean
Double                   Double                                  Double
Integer                  Integer                                 Integer
Null                     Null                                    N/A
Object                   Object                                  Object
Resource                 Resource                                N/A
String                   String                                  String
Unknown                  Unknown type                            N/A



is_numeric in action

<?php
   $item = 43;
   echo "The variable \$item is numeric: ".is_numeric($item)."<br />";
?>



PHP Data Types

 
Type                Description
Boolean             Possible values are True and False.
Float               Floating-point values.
Integer             Integer values.
String              Any series of ASCII characters 0?255. PHP strings are binary safe.
Array               An indexed list of other values. All data types are allowed as values.
Object              A class instance.
Resource            A handle to an internal data structure. This can be a database connection or a result set.



Returns true if $a is a floating-point number

<?
$a = 0.1;
echo( is_double($a) );
?>



Returns true if $a is an array

<?
 $a=array(0=>"zzzz", 
          "a"=>"aaa", 
          "b"=>"bbb", 
          "c"=>"ccc");

 echo(is_array($a));
?>



Returns true if $a is an integer

<?
$a = 0;
echo(is_integer($a));
?>



Returns true if $a is a string

<?
$a = "aa";
echo(is_string($a));
?>