Why Exception is not instance of Throwable?

Question

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?

Yes it does - https://eval.in/785678 – Styphon May 02 '17 at 16:35 — Styphon, May 02 '17 at 16:35

score 12 · Accepted Answer · edited Nov 01 '18 at 18:38

12

Throwable is the base interface for any object that can be thrown via a throw statement in PHP 7, including Error and Exception. And your code produces: $e is exception $e is throwable if you have PHP version >= 7

But you have PHP version 5.6.23, so Throwable interface is not available for this version.

edited Nov 01 '18 at 18:38

wp78de

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answered May 02 '17 at 16:38

arbogastes

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Had this problem while thinking I am on php7, but actually php7 was installed, but the 5.6 configured in the config file... luckly your post made me check that twice before searching for more. – Cagatay Ulubay Jul 26 '17 at 07:21

Why Exception is not instance of Throwable?

1 Answers1