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本文檔使用 php中文網手册 發布
(PHP 7)
ReflectionFunctionAbstract::hasReturnType — Checks if the function has a specified return type
Checks whether the reflected function has a return type specified.
此函数没有参数。
Returns TRUE
if the function is a specified return type, otherwise FALSE
.
Example #1 ReflectionFunctionAbstract::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)
Example #2 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.