# ReflectionFunctionAbstract::hasReturnType

(PHP 7, PHP 8)

ReflectionFunctionAbstract::hasReturnType — Checks if the function has a specified return type

### 说明

public ReflectionFunctionAbstract::hasReturnType(): bool

Checks whether the reflected function has a return type specified.

### 参数

此函数没有参数。

### 返回值

Returns `true` if the function is a specified return type, otherwise `false`.

### 示例

示例 #1 ReflectionFunctionAbstract::hasReturnType() example

`<?php
function to_int($param) : int {
return (int) $param;
}
$reflection1 = new ReflectionFunction('to_int');
var_dump($reflection1->hasReturnType());`

以上示例会输出：

    bool(true)

示例 #2 Usage on built-in functions

`<?php
$reflection2 = new ReflectionFunction('array_merge');
var_dump($reflection2->hasReturnType());`

以上示例会输出：

    bool(false)

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

- ReflectionFunctionAbstract::getReturnType() - Gets the specified return type of a function

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