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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