Question

I have a control flow question. In my company we create a lot of bool methods that return false if there was an error. Example:

public bool Foo(string path, string fileName, ref string error)
{
    if (path == null)
    {
        error = "path is null";
        return false;
    }
    path += fileName;
    return true;
}

As you can see it’s ugly. I want to use it with exceptions like so:

public voidFoo(string path, string fileName, ref string error)
{
    if (path == null)
    {
        throw new SomeException("Path is null.");
    }
    path += fileName;
    return true;
}

But we worry about the overhead. Should we?

Answer 1

If the exception is not thrown, then the overhead of your try...catch is negligable. So, the rule of thumb is:

• If the exception is likely to be thrown (i.e., if path == null is a “supported” scenario), use the return value.
• If the exception is unlikely, i.e., if path == null usually only happens if the developer using your function makes a mistake, then use an exception.