ReflectionFunctionAbstract::hasReturnType()

版本：php7

(PHP 7)

Checks if the function has a specified return type

说明

publicReflectionFunctionAbstract::hasReturnType(void) : bool

Checks whether the reflected function has a return type specified.

参数

此函数没有参数。

返回值

ReturnsTRUEif the function is a specified return type,otherwiseFALSE.

范例

Example #1ReflectionFunctionAbstract::hasReturnType()example

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

以上例程会输出：

bool(true)

Usage on built-in functions

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

以上例程会输出：

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