PHP 5.6.0 released

ReflectionParameter 类

(PHP 5)

简介

ReflectionParameter 取回了函数或方法参数的相关信息。

要自行检查函数的参数,首先创建一个 ReflectionFunctionReflectionMethod 的实例,然后使用它们的 ReflectionFunctionAbstract::getParameters() 方法来获取参数的数组。

类摘要

ReflectionParameter implements Reflector {
/* 属性 */
public $name ;
/* 方法 */
public bool allowsNull ( void )
public bool canBePassedByValue ( void )
final private void __clone ( void )
public __construct ( string $function , string $parameter )
public static string export ( string $function , string $parameter [, bool $return ] )
public ReflectionClass getClass ( void )
public ReflectionClass getDeclaringClass ( void )
public ReflectionFunctionAbstract getDeclaringFunction ( void )
public mixed getDefaultValue ( void )
public string getDefaultValueConstantName ( void )
public string getName ( void )
public int getPosition ( void )
public bool isArray ( void )
public bool isCallable ( void )
public bool isDefaultValueAvailable ( void )
public bool isDefaultValueConstant ( void )
public bool isOptional ( void )
public bool isPassedByReference ( void )
public string __toString ( void )
}

属性

name

参数的名称。只读,在尝试赋值的时候会抛出 ReflectionException

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User Contributed Notes 3 notes

up
1
fgm at riff dot org
6 years ago
The note about the signature of the ReflectionParameter constructor is actually incomplete, at least in 5.2.5: it is possible to use an integer for the second parameter, and the constructor will use it to return the n-th parameter.

This allows you to obtain proper ReflectionParameter objects even when documenting code from extensions which (strangely enough) define several parameters with the same name. The string-based constructor always returns the first parameter with the matching name, whereas the integer-based constructor correctly returns the n-th parameter.

So, in short, this works:
<?php
// supposing the extension defined something like:
// Some_Class::someMethod($a, $x, $y, $x, $y)
$p = new ReflectionParameter(array('Some_Class', 'someMethod'), 4);
// returns the last parameter, whereas
$p = new ReflectionParameter(array('Some_Class', 'someMethod'), 'y');
// always returns the first $y at position 2
?>
up
0
massimo at mmware dot it
7 years ago
I found these limitations using class ReflectionParameter from ReflectionFunction with INTERNAL FUNCTIONS (eg print_r, str_replace, ... ) :

1. parameter names don't match with manual: (try example 19.35 with arg "call_user_func" )
2. some functions (eg PCRE function, preg_match etc) have EMPTY parameter names
3. calling getDefaultValue on Parameters will result in Exception "Cannot determine default value for internal functions"
up
-1
killgecNOFSPAM at gmail dot com
7 years ago
Signature of constructor of ReflectionParameter correctly is:

public function __construct(array/string $function, string $name);

where $function is either a name of a global function, or a class/method name pair.
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