var_export
(PHP 4 >= 4.2.0, PHP 5)
var_export — Outputs or returns a parsable string representation of a variable
Описание
var_export() gets structured information about the given variable. It is similar to var_dump() with one exception: the returned representation is valid PHP code.
Список параметров
- expression
-
The variable you want to export.
- return
-
If used and set to TRUE, var_export() will return the variable representation instead of outputing it.
Note: This function internally uses the output buffering with this parameter so it can not be used inside ob_start() callback function.
Возвращаемые значения
Returns the variable representation when the return parameter is used and evaluates to TRUE. Otherwise, this function will return NULL.
Список изменений
| Версия | Описание |
|---|---|
| 5.1.0 | Possibility to export classes and arrays containing classes using the __set_state magic method. |
Примеры
Example#1 var_export() Examples
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_export($a);
?>
Результат выполнения данного примера:
array ( 0 => 1, 1 => 2, 2 => array ( 0 => 'a', 1 => 'b', 2 => 'c', ), )
<?php
$b = 3.1;
$v = var_export($b, true);
echo $v;
?>
Результат выполнения данного примера:
3.1
Example#2 Exporting classes since PHP 5.1.0
<?php
class A { public $var; }
$a = new A;
$a->var = 5;
var_export($a);
?>
Результат выполнения данного примера:
A::__set_state(array( 'var' => 5, ))
Example#3 Using __set_state (since PHP 5.1.0)
<?php
class A
{
public $var1;
public $var2;
public static function __set_state($an_array)
{
$obj = new A;
$obj->var1 = $an_array['var1'];
$obj->var2 = $an_array['var2'];
return $obj;
}
}
$a = new A;
$a->var1 = 5;
$a->var2 = 'foo';
eval('$b = ' . var_export($a, true) . ';'); // $b = A::__set_state(array(
// 'var1' => 5,
// 'var2' => 'foo',
// ));
var_dump($b);
?>
Результат выполнения данного примера:
object(A)#2 (2) { ["var1"]=> int(5) ["var2"]=> string(3) "foo" }
Примечания
Note: Variables of type resource couldn't be exported by this function.
Note: var_export() does not handle circular references as it would be close to impossible to generate parsable PHP code for that. If you want to do something with the full representation of an array or object, use serialize().