How to throw good exceptions?

Question

I heard you should never throw a string because there is a lack of information and you\'ll catch exceptions you dont expect to catch. What are good practice for throwing exc

Answer 1

As it has been already said use them for exceptional situations only.

Always provide a way for the user to avoid throwing an exception, eg. if you have method, that will throw if something goes wrong like this:

public void DoSomethingWithFile() {
    if(!File.Exists(..))
        throw new FileNotFoundException();
}

Provide another method for the user to call:

public bool CanDoSomething() {
    return File.Exists(..);
}

This way there the caller can avoid exceptions if he wants. Do not hesitate to throw if something is wrong - "fail fast", but always provide exception-free path.

Also keep your exception class hierarchy flat and take a look at the standard exceptions like InvalidStateException and ArgumentNullExcpetion.