International PHP Conference 2019 - Spring Edition

ReflectionFunctionAbstract::getReturnType

(PHP 7)

ReflectionFunctionAbstract::getReturnTypeGets the specified return type of a function

说明

public ReflectionType ReflectionFunctionAbstract::getReturnType ( void )

Gets the specified return type of a reflected function.

参数

此函数没有参数。

返回值

Returns a ReflectionType object if a return type is specified, NULL otherwise.

范例

Example #1 ReflectionFunctionAbstract::getReturnType() example

<?php

function to_int($param) : int {
    return (int) 
$param;
}

$reflection1 = new ReflectionFunction('to_int');
echo 
$reflection1->getReturnType();

以上例程会输出:

int

Example #2 Usage on built-in functions

<?php

$reflection2 
= new ReflectionFunction('array_merge');

var_dump($reflection2->getReturnType());

以上例程会输出:

null

This is because many internal functions do not have types specified for their parameters or return values. It is therefore best to avoid using this method on built-in functions.

参见

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