var_export
(PHP 4 >= 4.2.0, PHP 5, PHP 7)
var_export — Outputs or returns a parsable string representation of a variable
Description
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.
Parameters
-
expression -
The variable you want to export.
-
return -
If used and set to
TRUE, var_export() will return the variable representation instead of outputting it.
Return Values
Returns the variable representation when the return
parameter is used and evaluates to TRUE. Otherwise, this function will
return NULL.
Notes
Note:
When the
returnparameter is used, this function uses internal output buffering so it cannot be used inside an ob_start() callback function.
Changelog
| Version | Description |
|---|---|
| 5.1.0 | Possibility to export classes and arrays containing classes using the __set_state() magic method. |
Examples
Example #1 var_export() Examples
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_export($a);
?>
The above example will output:
array (
0 => 1,
1 => 2,
2 =>
array (
0 => 'a',
1 => 'b',
2 => 'c',
),
)
<?php
$b = 3.1;
$v = var_export($b, true);
echo $v;
?>
The above example will output:
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);
?>
The above example will output:
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);
?>
The above example will output:
object(A)#2 (2) {
["var1"]=>
int(5)
["var2"]=>
string(3) "foo"
}
Notes
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().
When var_export() exports objects, the leading backslash is not included in the class name of namespaced classes for maximum compatibility.
Note:
To be able to evaluate the PHP generated by var_export(), all processed objects must implement the magic __set_state method. Note that StdClass does not implement __set_state().
See Also
- print_r() - Prints human-readable information about a variable
- serialize() - Generates a storable representation of a value
- var_dump() - Dumps information about a variable
English translation
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Document created the 30/01/2003, last modified the 26/10/2018
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References
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