• 首页
  • vue
  • TypeScript
  • JavaScript
  • scss
  • css3
  • html5
  • php
  • MySQL
  • redis
  • jQuery
  • ReflectionFunctionAbstract::getReturnType()

    版本:php7

    (PHP 7)

    Gets the specified return type of a function

    说明

    publicReflectionFunctionAbstract::getReturnType(void) :ReflectionType

    Gets the specified return type of a reflected function.

    参数

    此函数没有参数。

    返回值

    Returns aReflectionTypeobject if a return type is specified,NULLotherwise.

    范例

    Example #1ReflectionFunctionAbstract::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
    

    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

    • ReflectionFunctionAbstract::hasReturnType() Checks if the function has a specified return type
    • ReflectionType::__toString() To string