Substring problem

Comments

• Stark Syria

  August 2010 edited August 2010

  Hi , have a good day
  
  The Error is very clear , I will try to Explain it in details :
  
  1) This One "Substring([Parameter1],1,1)" is try to select a string from paramter1
  Which start with character of index 1 and end at character of index 1
  
  For Example :
  if paramter1 = "Stark" then SubString([paramter1], 1,1) will give the result "t"
  BUT
  if paramter1 = "" then SubString([paramter1], 1,1) will throw an error because there is no character at Index 1 , paramter1 has Zero Characters
  
  And in your Attachment report Parameter1 = "" , and that is why you get an error !
  
  
  Solution :
  
  you have two ways :
  *) Give Paramter1 some value ,
  OR
  *) replace the SubString([paramter1], 1,1) With SubString([paramter1], 0,0)
  
  
  
  Hope this help
  
  
  
  
  P.S :
  I didn't know what are you trying to achieve , or why paramter1 has the value "" ?
• Keve G??bor hungary

  August 2010 edited August 2010

  Hello Stark!
  
  Thanks the answer!
  
  You right! But...
  
  I think that due the IIf condition, the Substring procedure should not be evaluate, because the Parameter1 length = 0.
  
  The right evaluation order is:
  
  <!--fonto:Courier New--><span style="font-family:Courier New"><!--/fonto-->IIf -> Length(Parameter1)>0 -> false -> Parameter2
  -> true -> Substring(Parameter1,1,1)<!--fontc--></span><!--/fontc-->
  
  If Parameter1 value is "" then Lenght(Parameter1) = 0.
  
  But i think the real evaluation start within.
  
  So, clarifying my question:
  Why evaluate the Substring function the engine, if Parameter1.Lengt()==0?
  
  [img]style_emoticons/<#EMO_DIR#>/unsure.gif" style="vertical-align:middle" emoid=":unsure:" border="0" alt="unsure.gif" /> regards, Gabor Keve[/img]

  Stark wrote: »

  Hi , have a good day
  
  The Error is very clear , I will try to Explain it in details :
  
  1) This One "Substring([Parameter1],1,1)" is try to select a string from paramter1
  Which start with character of index 1 and end at character of index 1
  
  For Example :
  if paramter1 = "Stark" then SubString([paramter1], 1,1) will give the result "t"
  BUT
  if paramter1 = "" then SubString([paramter1], 1,1) will throw an error because there is no character at Index 1 , paramter1 has Zero Characters
  
  And in your Attachment report Parameter1 = "" , and that is why you get an error !
  
  
  Solution :
  
  you have two ways :
  *) Give Paramter1 some value ,
  OR
  *) replace the SubString([paramter1], 1,1) With SubString([paramter1], 0,0)
  
  
  
  Hope this help
  
  
  
  
  P.S :
  I didn't know what are you trying to achieve , or why paramter1 has the value "" ?
• Stark Syria

  August 2010 edited August 2010

  You are welcome !
  

  Keve G??bor wrote: »

  I think that due the IIf condition, the Substring procedure should not be evaluate, because the Parameter1 length = 0.

  I was think the same , Until I saw your Question , because C# didn't do that
  

  string res = string.Empty;
  string paramter1 = "";
  string paramter2 = "text";
         
  res = paramter1.Length > 0 ? paramter1.Substring(1, 1) : paramter2;
  Console.WriteLine(res);
  

  
  

  Keve G??bor wrote: »

  So, clarifying my question:
  Why evaluate the Substring function the engine, if Parameter1.Lengt()==0?

  
  I think this is how fast report works , I really don't know much about it's engine , ( I am just a user for fast-report [img]style_emoticons/<#EMO_DIR#>/rolleyes.gif" style="vertical-align:middle" emoid=":rolleyes:" border="0" alt="rolleyes.gif" /> ) May be one of the makers can answer you ,[/img]