What is the convention in leaving If Then Else statement empty?

[Lampbert]

Hello,

Still new to programming, so probably a basic thing...

Whenever I do an If Then Else statement and I don't want it to do anything if the conditions are met, I just leave the Then part empty, like so:

Code: Pascal  [Select][+][-]

1. If a = a then begin
2.   // Do nothing
3. end
4. else begin
5.   DoSomething();
6. end;

Is this correct, or is there a more official, cleaner, conventional way to do this?

Thank you.

[winni]

Hi!

Ask George Bool and you get the following answer:

Code: Pascal  [Select][+][-]

1. If a <> a then begin
2.           DoSomething();
3.           end;
4.  

//  else Do nothing without typing


 Winni

[JuhaManninen]

Maybe:

Code: Pascal  [Select][+][-]

1. If a <> b then
2.   DoSomething();

I switched the second "a" to "b" because "a" never differs from "a".

[Thaddy]

Code: Pascal  [Select][+][-]

1. // assumes a is a Boolean.
2. case a of
3. true:Dosomething;
4. else; // do nothing
5. end;

[winni]

Dont confuse the newbie:

Case is for more  than 2 solutions.

For a boolean if then else  is enough.

Keep it simple, stupid!

Winni

[Thaddy]

Dont confuse the newbie:

Case is for more  than 2 solutions.

For a boolean if then else  is enough.

Keep it simple, stupid!

Winni

Well, based on your reply and common sense, if would suffice......no need for else.....(Fired... )
A simple matter of program flow.

[winni]

 Nothing to argue, but a lot of words.

[Lampbert]

Thanks for everyone's answer. I learned this new operator now.

[eljo]

Hello,

Still new to programming, so probably a basic thing...

Whenever I do an If Then Else statement and I don't want it to do anything if the conditions are met, I just leave the Then part empty, like so:

Code: Pascal  [Select][+][-]

1. If a = a then begin
2.   // Do nothing
3. end
4. else begin
5.   DoSomething();
6. end;

Is this correct, or is there a more official, cleaner, conventional way to do this?

Thank you.

just a thought why not

Code: Pascal  [Select][+][-]

1. If not (a = a) then begin
2.   DoSomething();
3. end;

[winni]

Hi!

As it was said above:

a=a  is always true. (In our solar system)

So reduce your example to

Code: Pascal  [Select][+][-]

1. { nothing}
2.  

But what you want  is

Code: Pascal  [Select][+][-]

1. if a <> b then DoSomething;

Seems you have to learn something about boolean operators.

You also  can write

Code: Pascal  [Select][+][-]

1. if NOT (a=b) then DoSomething;

But if you insist on the useless if condition - you can drop the begin end

Code: Pascal  [Select][+][-]

1. if a= b then else DoSomething;

Winni