topic Re: Do While syntax bug in QlikView

Do While syntax bug

Thu, 25 Oct 2012 13:40:56 GMT

on a number of occations i have had to change the syntax of using a variable in the condition part of a do while loop.

on some occations $(varName) is needed, some cases '$(varName)' is needed, some cases varName is needed (and appears in red [feild]?) and in some cases 'varName' is needed.

just something which could be improved on

thanks for your consideration

rhys bradbury

Re: Do While syntax bug

Fri, 26 Oct 2012 11:06:48 GMT

BUMP for QV R+D team to see

Re: Do While syntax bug

jonathandienst — Fri, 26 Oct 2012 11:57:03 GMT

Rhys

These all mean different things. Let me attempt to explain them:

$(varName) - returns the expansion of the variable (performed before the statement is executed). This is the same as typing the contents of the variable. If the contents are an expression, it will be evaluated when the statement is executed. You can use this form when the variable is defined (for example):

'$(varName)' - also return the expansion, but treats the contents as a string. In other word, when the statement is executed, the variable's content will be placed in the string and not evaluated. For example, if variable v1 contains 2012/10/26, then

varName - returns the value of the variable (like a conventional variable in other programming languages). You can use this form when the variable is defined as (for example):

'varName' - will simply return a string containing 'varName', and makes no reference to the variable at all.

Hope that helps to clear up the situation.

Jonathan

Re: Do While syntax bug

Fri, 26 Oct 2012 12:41:13 GMT

Thankyou for such a comprehensive reply, this is very useful knowledge and i will be using this as a reference when dealing with syntax from now on.

Thankyou once again,

Rhys Bradbury

Re: Do While syntax bug

jonathandienst — Fri, 26 Oct 2012 14:03:52 GMT

Rhys

You're welcome. Perhaps this sort of thing should be in a tutorial manual

Regards

Jonathan

Re: Do While syntax bug

Mon, 29 Oct 2012 12:49:12 GMT

Agreed

Re: Do While syntax bug

Tue, 04 Feb 2014 19:30:39 GMT

I just liked this answer... it's hugely helpful! I wish I could do more than just like it... give it stars, and banners, and awards.

This explanation needs to be easier to find!