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#182017 - 2007-10-28 12:06 AM

Is the variable empty?

_Andy_ Offline

Fresh Scripter

Registered: 2007-10-27
Posts: 17
Loc: Sydney, Australia

I have a little issue with checking if a variable is empty...

If I use the "get" command and just press "Enter" then the variable is not blank??? How can I get the code below to give the same result?

Code:

break on
$= SetOption('Explicit','ON')
$= SetOption('WrapAtEOL','ON')
$= SetOption('NoVarsInStrings','ON')
$= SetTitle('Info...')

Dim $myvar
$myvar = ''

?
? 'Myvar: |' + $myvar + '|'
?
If $myvar = ''
  ? 'Empty variable'
Else
  ? 'Not so empty...'
Endif
?
? 'Length of myvar: ' + len($myvar)
?
?
? 'Enter a value for myvar: '
flushkb
get $myvar
?
? 'Myvar: |' + $myvar + '|'
?
If $myvar = ''
  ? 'Empty variable'
Else
  ? 'Not so empty...'
Endif
?
? 'Length of myvar: ' + len($myvar)
?
Get $

Regards,
Andy

_________________________
Regards,
Andy.

--Just shoot me, please.--

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#182018 - 2007-10-28 12:23 AM Re: Is the variable empty? [Re: _Andy_]
Howard Bullock Howard Bullock KiX Supporter Registered: 2000-09-15 Posts: 5809 Loc: Harrisburg, PA USA	A null string is not the same as empty. Instead of If $myvar = '' try ? VarTypeName($myvar) and determine if the state matches one defined in the VarTypeName results table. You can then set up your If...Else...Endif construct. _________________________ Home page: http://www.kixhelp.com/hb/
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#182020 - 2007-10-28 12:48 AM Re: Is the variable empty? [Re: Howard Bullock]
Howard Bullock Howard Bullock KiX Supporter Registered: 2000-09-15 Posts: 5809 Loc: Harrisburg, PA USA	After testing, I think that KiXtart is behaving properly. It is your example that is causing your confusion. Let's examine the issue closer... When your hit the Carriage Return, $myvar is not longer empty. It contains ascii character 13 (the CR). The way you you output the text the text is printed ? 'Myvar: \|' Then you print ascii character 13 held in $myvar which returns the cursor to the front of the line. Then the last pipe character is printed over the "M" leaving you the text "\|yvar: \|". The length($myvar) correctly prints 1. You can see what character is in your variable by printing ASC($myvar). _________________________ Home page: http://www.kixhelp.com/hb/
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#182023 - 2007-10-28 04:19 AM Re: Is the variable empty? [Re: Howard Bullock]
_Andy_ _Andy_ Fresh Scripter Registered: 2007-10-27 Posts: 17 Loc: Sydney, Australia	Thank you. _________________________ Regards, Andy. --Just shoot me, please.--
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#182037 - 2007-10-29 03:10 AM Re: Is the variable empty? [Re: _Andy_]
Howard Bullock Howard Bullock KiX Supporter Registered: 2000-09-15 Posts: 5809 Loc: Harrisburg, PA USA	Thinking about your script's usage of "GET" which captures a single keyboard input, I think you can simply check to see if you find the expected key stroke using a Select...Case...EndSelect construct and use a "Case 1" to trap any unexpected key press. _________________________ Home page: http://www.kixhelp.com/hb/
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