在PHP

Question

中按類（instanceof）切換可以用開關替換if(.. instanceof ...), elseif(... instanceof ...), ...塊嗎？

例如：

<?php 
$class = ..... //some class 

if($class instanceof SomeClass) { 
    //do something 
} elseif($class instanceof SomeAnotherClass) { 
    //do something else 
} 

Answer 1

下面是更正確的：

$class = get_class($objectToTest); 

switch($class) { 
    case TreeRequest::class: 
     echo "tree request"; 
     break; 
    case GroundRequest::class: 
     echo "ground request"; 
     break; 
} 

通過這種方式正確比較命名空間（您不必輸入它們），並且如果命名空間或類名稱等任何更改都會發生體面的IDE錯誤，從而通知您代碼已損壞。

Answer 2

一些這樣的：

$class = get_class($objectToTest); 

switch($class) { 
    case 'TreeRequest': 
     echo "tree request"; 
     break; 
    case 'GroundRequest': 
     echo "ground request"; 
     break; 
} 

或者這樣：

switch(true) { 
    case $objectToTest instanceof TreeRequest: 
     echo "tree request"; 
     break; 
    case $objectToTest instanceof GroundRequest: 
     echo "ground request"; 
     break; 
}