Question

I need to know what is better (for performance and else), Using Try Catch when expecting error and there is no alternate scenario when error hapened or check the value first ?

For Example (VB.net):
If I need to fill text box by value from database (from Data Reader for example), and I expecting some null values, and if value is null I will leave textbox empty.

now I have to ways to do this:

try
  textbox1.text = DR("Name")
catch
end try

now if column Name contain null value the error will raise and textbox1 still empty.

If Not IsDBNull(DR("Name")) Then textbox1.Text = DR("Name")

what is better ?

Thank you so much.

Answer 1

Do not use exception handling as flow control. Ever.

So – check the value instead of Try/Catch.

When an exception is thrown the runtime has quite a lot of work to do – if you expect null values – always check for them instead of relying on exceptions.