ReflectionFunctionAbstract::hasReturnType

(PHP 7)

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

说明

public bool ReflectionFunctionAbstract::hasReturnType ( void )

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 .

范例

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.

参见

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