Access Expression Editor - Newbie to access reports

Question

I am new to Access reports and forms. Yes I hate admitting it. I am familiar with the database part but not with reports and forms.

I have come across this peculiar expression in Access expression builder which i cant deconstruct

=IIf(([value1] & ""="") Or ([value2] & ""=""),"",[value3])

Please understand that I have sufficient experience with Crystal Reports and i understand what an iif statement is .

But I have not come across anything like this

1. What exactly does & ""="" do?
2. Is this some sort of regular expression in Access?
3. Can you help me by providing links so that I can read up on this in depth?

Thanks a ton in advance Cheers!

Answer 1

It is appending an empty string to the value to avoid Null.

You could say it this way:

Value Is Null Or Value = ""

Further explanation re comment

Let us say Value1 is Null

Value1 is not equal to ""

However

Value1 & "" is equal to ""

Let us say Value1 = ""

Value1 is not equal to Null

However

Value1 & "" is equal to ""

Let us say Value1 = "abc"

Value1 & "" is equal to "abc"