为什么Exception不是Throwable的实例？(Why Exception is not instance of Throwable?)

 我认为在所有编程语言中Exception类都是Throwable接口的实例。 
 
 看一下下面的代码，它显示Exception不是php中的Throwable实例。 
 
try {

    throw new InvalidArgumentException("error message");

} catch (InvalidArgumentException $e) {

    if ($e instanceof Exception) {
        echo '$e is exception';             // this line gets executed
    }

    if ($e instanceof Throwable) {
        echo '$e is throwable';             // but this one never
    }

}
 
 它使链接异常成为​​问题，其中Exception类构造函数在其最后一个参数中接受Throwable 。 
 
 php版本： 5.6.23 
 
 有解决方案吗 

I think in all programming languages Exception class is instance of Throwable interface.
 
Take a look at following code which shows Exception is not instance of Throwable in php.
 
try {

    throw new InvalidArgumentException("error message");

} catch (InvalidArgumentException $e) {

    if ($e instanceof Exception) {
        echo '$e is exception';             // this line gets executed
    }

    if ($e instanceof Throwable) {
        echo '$e is throwable';             // but this one never
    }

}
 
It makes problem with chaining exceptions where Exception class constructor accepts Throwable in it's last argument.
 
php version: 5.6.23
 
Any solution?

原文：https://stackoverflow.com/questions/43742976