在PHP

Question

中按类（instanceof）切换可以用开关替换if(.. instanceof ...), elseif(... instanceof ...), ...块吗？

例如：

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

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

Answer 1

下面是更正确的：

$class = get_class($objectToTest); 

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

通过这种方式正确比较命名空间（您不必输入它们），并且如果命名空间或类名称等任何更改都会发生体面的IDE错误，从而通知您代码已损坏。

Answer 2

一些这样的：

$class = get_class($objectToTest); 

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

或者这样：

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