PHP Conference Japan 2024

var_representation

(PECL var_representation >= 0.1.0)

var_representationReturns a short, readable, parsable string representation of a variable

Description

var_representation(mixed $value, int $flags = 0): string

var_representation() (from the var_representation PECL) returns a string with structured information about the given variable. It is similar to var_export() with differences in indentation, string escaping, and array representations.

Parameters

value

The variable to generate a representation of.

flags

Bitmask consisting of VAR_REPRESENTATION_SINGLE_LINE, VAR_REPRESENTATION_UNESCAPED. The behaviour of these constants is described on the var_representation constants page.

Return Values

Returns the variable representation.

Examples

Example #1 var_representation() Examples

<?php
$a
= [1, 2, ['key' => 'value']];
echo
var_representation($a), "\n";
echo
var_representation($a, VAR_REPRESENTATION_SINGLE_LINE), "\n";
?>

The above example will output:

[
  1,
  2,
  [
    'key' => 'value',
  ],
]
[1, 2, ['key' => 'value']]

Example #2 Escaping control characters

<?php
echo var_representation("Content-Length: 123\r\n");

The above example will output:

"Content-Length: 123\r\n"

Example #3 Exporting stdClass

<?php
$person
= new stdClass;
$person->name = 'ElePHPant ElePHPantsdotter';
$person->website = 'https://php.net/elephpant.php';

echo
var_representation($person);

The above example will output:

(object) [
  'name' => 'ElePHPant ElePHPantsdotter',
  'website' => 'https://php.net/elephpant.php',
]

Example #4 Exporting classes

<?php
class A { public $var; }
$a = new A;
$a->var = 5;
echo
var_representation($a);
?>

The above example will output:

\A::__set_state([
  'var' => 5,
])

Example #5 Using __set_state()

<?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(
'$b = ' . var_representation($a) . ';'); // $b = \A::__set_state([
// 'var1' => 5,
// 'var2' => 'foo',
// ]);
var_dump($b);
?>

The above example will output:

object(A)#2 (2) {
  ["var1"]=>
  int(5)
  ["var2"]=>
  string(3) "foo"
}

See Also

  • var_export() - Outputs or returns a parsable string representation of a variable

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