vb.net if shorthand

Question

is there a way to use shorthand to do something like this?

If Not txtBookTitle.Text = String.Empty Then
  objBook.DisplayName = txtBookTitle.Text
End If

http://stackoverflow.com/questions/28377/iif-vs-if – djv Mar 13 '13 at 22:52 — djv, Mar 13 '13 at 22:52

score 41 · Accepted Answer · answered Mar 13 '13 at 19:08

41

objBook.DisplayName = If(Not (txtBookTitle.Text = String.Empty), txtBookTitle.Text, objBook.DisplayName)

answered Mar 13 '13 at 19:08

Mike Corcoran

9

This is [1 character longer than the original](http://www.lettercount.com/), including the spaces. :) – Victor Zakharov Mar 13 '13 at 19:26
3

don't blame me, blame vb for not implementing a proper ternary operator :P – Mike Corcoran Mar 13 '13 at 20:46
1

Maybe I'm missing something, but doesn't the <> operator work on strings? Why the use of Not? – Chris Dunaway Mar 14 '13 at 14:50
1

i just basically followed the code provided from the question. – Mike Corcoran Mar 14 '13 at 14:52

score 7 · Answer 2 · answered Mar 13 '13 at 19:13

7

There are two version of the if statement shorthand. Either If(expression, true part, false part) or If(expression, false part)

objBook.DisplayName = If(String.IsNullOrEmpty(txtBookTitle.Text), txtBookTitle.Text)

answered Mar 13 '13 at 19:13

JayGee

score 7 · Answer 3 · answered Mar 13 '13 at 19:19

7

Following code is similar to your three line of code:

objBook.DisplayName = IIF(String.IsNullorEmpty(txtBookTitle.Text),objBook.DisplayName, txtBookTitle.Text)

answered Mar 13 '13 at 19:19

Romil Kumar Jain

4

i dont recommend using IIF. *Both parameters WILL be evaluated* and that can produce unexpected results for example *if you use functions.* Consider this `IIF(TRUE,JustPrintOK(),ImplodeTheUniverse())`... we are doomed since both functions will be executed regardless of the condition. For VB >= 9 just use `IF` just like your example, it will work without this problem. – Sharky Mar 13 '14 at 07:21
1

Exactly, one should use `If` and `AndAlso` / `OrElse` instead – specializt Aug 22 '15 at 09:29

score 5 · Answer 4 · answered Mar 13 '13 at 19:31

5

This is the shortest version (81 character):

If txtBookTitle.Text <> String.Empty Then objBook.DisplayName = txtBookTitle.Text

And I would prefer this for debug-ability. Also easily convertible to C#.

answered Mar 13 '13 at 19:31

Victor Zakharov

3

I think it's also clearer than ... If Not txtBookTitle.Text = String.Empty – Derek Tomes Mar 13 '13 at 22:30

4 Answers4