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sham · May 7th, 2005, 12:15 AM

What is difference between NULL ,zero length string ,Empty?

Rory · May 7th, 2005, 9:49 AM

Null means a variable contains absolutely nothing, and is only valid for Variant types: it will evaluate to null - for instance a long cannot be null because it defaults to 0. A zero length string is a string of zero length "" (not to be confused with vbNullString which is a string that is null used for certain API calls). An optional argument is empty when nothing is specified and IsEmpty and IsMissing will evaluate to true, but any attempts to manipulate the missing argument will raise an error.
Hope that helps.

May 7th, 2005, 12:15 AM	#1
sham Newbie Join Date: Mar 2005 Posts: 29 Rep Power: 0	What is difference between NULL ,zero length string ,Empty? What is difference between NULL ,zero length string ,Empty?

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May 7th, 2005, 9:49 AM	#2
Rory Expert Programmer Join Date: Jan 2005 Location: London Posts: 542 Rep Power: 4	Null means a variable contains absolutely nothing, and is only valid for Variant types: it will evaluate to null - for instance a long cannot be null because it defaults to 0. A zero length string is a string of zero length "" (not to be confused with vbNullString which is a string that is null used for certain API calls). An optional argument is empty when nothing is specified and IsEmpty and IsMissing will evaluate to true, but any attempts to manipulate the missing argument will raise an error. Hope that helps.

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