Sieu ho tro Homepage
Forum Home Forum Home > Information Technology > The programming language > Java, Java script
  New Posts New Posts RSS Feed - VBScript Keywords
  FAQ FAQ  Forum Search   Events   Register Register  Login Login


VBScript Keywords

 Post Reply Post Reply
Author
Message
guest View Drop Down
Guest
Guest
Avatar

Joined: 16 November 2007
Location: Vietnam
Status: Offline
Points: 16
Post Options Post Options   Thanks (0) Thanks(0)   Quote guest Quote  Post ReplyReply Direct Link To This Post Topic: VBScript Keywords
    Posted: 26 February 2008 at 10:31

VBScript Keywords

Keyword Description
empty

Used to indicate an uninitialized variable value. A variable value is uninitialized when it is first created and no value is assigned to it, or when a variable value is explicitly set to empty.

Example:
dim x   'the variable x is uninitialized!
x="ff"   'the variable x is NOT uninitialized anymore
x=empty   'the variable x is uninitialized!

Note: This is not the same as Null!!

isEmpty

Used to test if a variable is uninitialized.

Example: If (isEmpty(x)) 'is x uninitialized?

nothing Used to indicate an uninitialized object value, or to disassociate an object variable from an object to release system resources.

Example: set myObject=nothing

is nothing Used to test if a value is an initialized object.

Example: If (myObject Is Nothing) 'is it unset?

Note: If you compare a value to Nothing, you will not get the right result! Example: If (myObject = Nothing) 'always false!

null Used to indicate that a variable contains no valid data.

One way to think of Null is that someone has explicitly set the value to "invalid", unlike Empty where the value is "not set".

Note: This is not the same as Empty or Nothing!!

Example: x=Null 'x contains no valid data

isNull Used to test if a value contains invalid data.

Example: if (isNull(x)) 'is x invalid?

true Used to indicate a Boolean condition that is correct (true has a value of -1)
false Used to indicate a Boolean condition that is not correct (false has a value of 0)
Back to Top
Sponsored Links


Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.064 seconds.
bao ky nam , Thuoc nam ky dieu
C?a thp ch?ng chy,cua thep chong chay,c?a ch?ng chy,cua chong chay,c?a nh?a abs,cua nhua abs,c?a abs,cua abs,cua thep van go,c?a thp vn g?,c?a thp an ton,cua thep an toan,c?a cu?n ch?ng chy,cua cuon chong chay,c?a g? ch?ng chy,cua go chong chay,c?a tru?t t? d?ng,cua truot tu dong,c?a knh ch?ng chy,cua kinh chong chay