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PHP - Manual: var_representation

2024-11-13

var_representation

(PECL var_representation >= 0.1.0)

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

说明

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.

参数

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.

返回值

Returns the variable representation.

范例

示例 #1 var_representation() Examples

<?php
$a 
= [12, ['key' => 'value']];
echo 
var_representation($a), "\n";
echo 
var_representation($aVAR_REPRESENTATION_SINGLE_LINE), "\n";
?>

以上例程会输出:

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

示例 #2 Escaping control characters

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

以上例程会输出:

"Content-Length: 123\r\n"

示例 #3 Exporting stdClass

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

echo 
var_representation($person);

以上例程会输出:

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

示例 #4 Exporting classes

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

以上例程会输出:

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

示例 #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);
?>

以上例程会输出:

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

参见

  • var_export() - 输出或返回变量的可解析字符串表示
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官方地址:https://www.php.net/manual/en/function.var-representation.php

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