I'm converting an old timed script from VB to C# and I need help with understanding what an If statement's purpose is.

The code I need help with is:

... And If(cp.JobTitle, String.Empty) = String.Empty And ...

This is part of a SQL query and the cp.JobTitle in the database is nullable string field.

Any help is appreciated!

CodePudding user response：

No, that is not part of a SQL query. Perhaps it's part of a LINQ query or some code that constructs a SQL query but there's nothing to do with SQL there.

Anyway, that VB code is using the If operator with two operands. The equivalent of this VB:

If(cp.JobTitle, String.Empty) = String.Empty

is this C#:

(cp.JobTitle ?? string.Empty) == string.Empty

It's saying to use cp.JobTitle unless it's Nothing, in which case use String.Empty. A better way to write functionally equivalent VB would be this:

String.IsNullOrEmpty(cp.JobTitle)

I hope the equivalent C# to that is obvious.

By the way, that VB code really ought to be using AndAlso rather than And. If you would use && in C# rather than &, which pretty much everyone would, then you should be using AndAlso in VB rather than And. In both cases, you should only use the other if you explicitly don't want short-circuiting.