If Statement

   Hi All,
How exactly does the If statement work?
a := 1;
b := 2;
c := 3;
If I were to use the following
If(A<>B,C=A,C=B);
What does C now hold?
From testing the 2nd & 3rd arguments are purley assignments not areas were code can be placed. I.e. C=A
If(A<>B,"A","B");
In this case here "A" will be printed.
Neil.

Edited by NeilW

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NeilW Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 06 Aug 2006 Location: Australia Posts: 8	Post Options Post Reply Quote NeilW Report Post Quote Reply Topic: If Statement Posted: 15 Aug 2006 at 9:23pm
	Hi All, How exactly does the If statement work? a := 1; b := 2; c := 3; If I were to use the following If(A<>B,C=A,C=B); What does C now hold? From testing the 2nd & 3rd arguments are purley assignments not areas were code can be placed. I.e. C=A If(A<>B,"A","B"); In this case here "A" will be printed. Neil. Edited by NeilW

chart rider Members Profile Send Private Message Find Members Posts Add to Buddy List Regular Joined: 25 Sep 2004 Location: Australia Posts: 96	Post Options Post Reply Quote chart rider Report Post Quote Reply Posted: 17 Aug 2006 at 6:29pm
	Neil You appear to have answered your question? The 2nd argument is the result if the 1st code is true, while the 3rd assignment is the result if the 1st code is false. CR

NeilW Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 06 Aug 2006 Location: Australia Posts: 8	Post Options Post Reply Quote NeilW Report Post Quote Reply Posted: 18 Aug 2006 at 5:46pm
	Hi, Yes and no, what is the value of C in the first question? If I have A:=4 A=5 A=6 A=7 Now what is the value of A? It is 4 so with the following K:=4 if(true,K=5,K=6) would you expect K to now equal 4 or 5? My testing shows K=4 You can only assign a variable once and it almost appears that the k=5 in the above IF is not an assigment but a comparison. if you try the following K:=4 if(true,k:=5,K:=6) you get syntax error messages. Neil.

scrooge Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 27 Jun 2006 Posts: 13	Post Options Post Reply Quote scrooge Report Post Quote Reply Posted: 22 Aug 2006 at 12:00pm
	I think you are correct that = leads to a comparison not an assignment. Therefore the expression If(A<>B,C=A,C=B) will return false if A<>B and C<>A, true if A<>B and C=A and so on. To assign a value to C try this: C:= if(A<>B,A,B)

zorro Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 17 Apr 2005 Posts: 17	Post Options Post Reply Quote zorro Report Post Quote Reply Posted: 29 Aug 2006 at 9:01pm
	Yes, this is correct. = is a comparison, and will return either 1 or zero depending on whether the two variables are the same, but it doesn't actually store anything in either variable. Whereas := is an assignment. Though they both look similar, they're very different in what they do. Each variable can only be assigned to once.

NeilW Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 06 Aug 2006 Location: Australia Posts: 8	Post Options Post Reply Quote NeilW Report Post Quote Reply Posted: 29 Aug 2006 at 9:16pm
	Hi Zorro, Your last statement was in reality the final answer. "Each variable can only be assigned to once. " I have not found in the Help where this is actually stated, perhaps some more generalised syntax help would not go astray. I personally program in Pascal as well as C and I'm aware of the differances between a comparison and a asssignment. Both of the above languages are different in these areas. It was in Bullcharts scripting language, that allowed me to appear to do some assigning and also the gotcha of only being aloud to assign a variables once that caught me. This once only assigmnet I find to be a pain in the <bleep> Just out of interest, I wonder what the result of A is - A := If(1=2,3=3,4=4); Does A = True ?? Neil. Edited by NeilW