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Problems with attributes in php object-oriented
- WBOYOriginal
- 2016-12-01 00:25:51996browse
class play{
<code>private $message = null;
public function __construct(){
}
public function callback(event $event){
$this->message = $event->click();
...
}</code>
}
Please tell me why you need to add event before $event in public function callback(event $event)? What does the event here do?
Thank you
Reply content:
class play{
<code>private $message = null;
public function __construct(){
}
public function callback(event $event){
$this->message = $event->click();
...
}</code>
}
Please tell me why you need to add event before $event in public function callback(event $event)? What does the event here do?
Thank you
Type declaration: The formal parameter $event must be an instance of (class/interface) event or an instance of a subclass of event (or a class that implements the event interface)
Thank you, that is the parameter type restriction of PHP function. That is, when you call $play->callback($event), if $event is not of type event, an error will be reported. The following picture is a table of the types that PHPfunction parameters can be set.
Strictly limit input types.