ReflectionParameter 类

(PHP 5, PHP 7)

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 ReflectionFunction 或 ReflectionMethod 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 ReflectionType getType ( void )

public bool hasType ( 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 bool isVariadic ( 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。

ReflectionParameter::allowsNull — Checks if null is allowed
ReflectionParameter::canBePassedByValue — Returns whether this parameter can be passed by value
ReflectionParameter::__clone — Clone
ReflectionParameter::__construct — Construct
ReflectionParameter::export — Exports
ReflectionParameter::getClass — Get the type hinted class
ReflectionParameter::getDeclaringClass — Gets declaring class
ReflectionParameter::getDeclaringFunction — Gets declaring function
ReflectionParameter::getDefaultValue — Gets default parameter value
ReflectionParameter::getDefaultValueConstantName — Returns the default value's constant name if default value is constant or null
ReflectionParameter::getName — Gets parameter name
ReflectionParameter::getPosition — Gets parameter position
ReflectionParameter::getType — Gets a parameter's type
ReflectionParameter::hasType — Checks if parameter has a type
ReflectionParameter::isArray — Checks if parameter expects an array
ReflectionParameter::isCallable — Returns whether parameter MUST be callable
ReflectionParameter::isDefaultValueAvailable — Checks if a default value is available
ReflectionParameter::isDefaultValueConstant — Returns whether the default value of this parameter is constant
ReflectionParameter::isOptional — Checks if optional
ReflectionParameter::isPassedByReference — Checks if passed by reference
ReflectionParameter::isVariadic — Checks if the parameter is variadic
ReflectionParameter::__toString — To string

User Contributed Notes

fgm at riff dot org 11-May-2008 09:44


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


?>

killgecNOFSPAM at gmail dot com 25-Jul-2007 02:53


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.

massimo at mmware dot it 18-Jul-2007 05:58


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"

ReflectionParameter 类

简介

类摘要

属性

Table of Contents

User Contributed Notes