ReflectionFunctionAbstract::getReturnType

(PHP 7, PHP 8)

ReflectionFunctionAbstract::getReturnType — Gets the specified return type of a function

说明

public ReflectionFunctionAbstract::getReturnType ( ) : ReflectionType|null

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

示例 #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

示例 #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