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ReflectionProperty::__construct

(PHP 5, PHP 7, PHP 8)

ReflectionProperty::__constructConstruct a ReflectionProperty object

说明

public ReflectionProperty::__construct(object|string $class, string $property)

参数

class

Either a string containing the name of the class to reflect, or an object.

property

The name of the property being reflected.

错误/异常

Trying to get or set private or protected class property's values will result in an exception being thrown.

示例

示例 #1 ReflectionProperty::__construct() example

<?php

class Str
{
public
$length = 5;
}

// Create an instance of the ReflectionProperty class
$prop = new ReflectionProperty('Str', 'length');

// Print out basic information
printf(
"===> The%s%s%s%s property '%s' (which was %s)\n" .
" having the modifiers %s\n",
$prop->isPublic() ? ' public' : '',
$prop->isPrivate() ? ' private' : '',
$prop->isProtected() ? ' protected' : '',
$prop->isStatic() ? ' static' : '',
$prop->getName(),
$prop->isDefault() ? 'declared at compile-time' : 'created at run-time',
var_export(Reflection::getModifierNames($prop->getModifiers()), true)
);

// Create an instance of Str
$obj= new Str();

// Get current value
printf("---> Value is: ");
var_dump($prop->getValue($obj));

// Change value
$prop->setValue($obj, 10);
printf("---> Setting value to 10, new value is: ");
var_dump($prop->getValue($obj));

// Dump object
var_dump($obj);

?>

以上示例的输出类似于:

===> The public property 'length' (which was declared at compile-time)
     having the modifiers array (
  0 => 'public',
)
---> Value is: int(5)
---> Setting value to 10, new value is: int(10)
object(Str)#2 (1) {
  ["length"]=>
  int(10)
}

示例 #2 Getting value from private and protected properties using ReflectionProperty class

<?php

class Foo
{
public
$x = 1;
protected
$y = 2;
private
$z = 3;
}

$obj = new Foo;

$prop = new ReflectionProperty('Foo', 'y');
$prop->setAccessible(true);
var_dump($prop->getValue($obj)); // int(2)

$prop = new ReflectionProperty('Foo', 'z');
$prop->setAccessible(true);
var_dump($prop->getValue($obj)); // int(2)

?>

以上示例的输出类似于:

int(2)
int(3)

参见

添加备注

用户贡献的备注 1 note

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5
geoffsmiths at hotmail dot com
7 years ago
At example #2: the comment // int(2) is stated while the value for the private property is actually 3. (private $z = 3;)

var_dump($prop->getValue($obj)); // This should be int(3)
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