no `catch (e: MyException if e.foo = 25) { .. }`??

# announcements

[vaskir]

no catch (e: MyException if e.foo = 25) { .. }??

[robin]

Nope. But

catch (e: MyException) {
   if (e.foo == 25) {
   ...
   }
}

works fine.

[vaskir]

🙂

[robin]

...except you'll probably need to rethrow in the else block to imitate your example.

[vaskir]

try {
//    ...
} catch (e: MyException) {
    if (e.code == 25) {
        // do specific stuff
    } else {
        // do common stuff
    }

} catch (e: Exception) {
    // do common stuff
}

[vaskir]

so I have to duplicate "do common stuff"

[vaskir]

if C#/F# there are guards

[vaskir]

like this:

try 
    ...
with 
| :? Exn1 as e when e.bar = 23 -> ...
| FooException(25) -> ...
| _ -> ...

[robin]

That's not really possible in kotlin, unfortunately. If you're already catching Exception though, you can do this instead:

try {
//    ...
} catch (e: Exception) {
    if (e is MyException && e.code == 25) {
        // do specific stuff
    } else {
        // do common stuff
    }
}

[vaskir]

ah, this looks better

[vaskir]

thanks

[robin]

No problem

[robin]

Oh and you can of course also use a when statement instead if you have more cases to check.