# ReflectionParameter::getType

(PHP 7, PHP 8)

ReflectionParameter::getType — Gets a parameter's type

### 说明

public ReflectionParameter::getType(): ?ReflectionType

Gets the associated type of a parameter.

### 参数

此函数没有参数。

### 返回值

Returns a ReflectionType object if a parameter type is specified, `null` otherwise.

### 示例

示例 #1 ReflectionParameter::getType() Usage as of PHP 7.1.0

As of PHP 7.1.0, ReflectionType::__toString() is deprecated, and ReflectionParameter::getType() may return an instance of ReflectionNamedType. To get the name of the parameter type, ReflectionNamedType() is available in this case.

`<?php
function someFunction(int $param, $param2) {}
$reflectionFunc = new ReflectionFunction('someFunction');
$reflectionParams = $reflectionFunc->getParameters();
$reflectionType1 = $reflectionParams[0]->getType();
$reflectionType2 = $reflectionParams[1]->getType();
assert($reflectionType1 instanceof ReflectionNamedType);
echo $reflectionType1->getName(), PHP_EOL;
var_dump($reflectionType2);
?>`

以上示例会输出：

    int
    NULL

示例 #2 ReflectionParameter::getType() Usage before PHP 7.1.0

`<?php
function someFunction(int $param, $param2) {}
$reflectionFunc = new ReflectionFunction('someFunction');
$reflectionParams = $reflectionFunc->getParameters();
$reflectionType1 = $reflectionParams[0]->getType();
$reflectionType2 = $reflectionParams[1]->getType();
echo $reflectionType1, PHP_EOL;
var_dump($reflectionType2);
?>`

以上示例在 PHP 7.0 中的输出：

    int
    NULL

示例 #3 ReflectionParameter::getType() Usage in PHP 8.0.0 and later

As of PHP 8.0.0, this method may return a ReflectionNamedType instance or a ReflectionUnionType instance. The latter is a collection of the former. To analyze a type, it is often convenient to normalize it to an array of ReflectionNamedType objects. The following function will return an array of `0` or more ReflectionNamedType instances.

`<?php
function getAllTypes(ReflectionParameter $reflectionParameter): array
{
$reflectionType = $reflectionParameter->getType();
if (!$reflectionType) return [];
return $reflectionType instanceof ReflectionUnionType
? $reflectionType->getTypes()
: [$reflectionType];
}
?>`

### 参见

- ReflectionParameter::hasType() - Checks if parameter has a type
- ReflectionType::__toString() - To string

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