Example of "using exceptions to control flow" [closed]

Question

What would a piece of code which "uses exceptions to control flow" look like? I've tried to find a direct C# example, but cannot. Why is it bad?

Thanks

Answer 1

By definition, an exception is an occurrence which happens outside the normal flow of your software. A quick example off the top of my head is using a FileNotFoundException to see if a file exists or not.

try
{
    File.Open(@"c:\some nonexistent file.not here");
}
catch(FileNotFoundException)
{
    // do whatever logic is needed to create the file.
    ...
}
// proceed with the rest of your program.

In this case, you haven't used the File.Exists() method which achieves the same result but without the overhead of the exception.

Aside from the bad usage, there is overhead associated with an exception, populating the properties, creating the stack trace, etc.