Jump to content

Why can't we append Null to a string?


Recommended Posts

Here is some code:

ConsoleWrite("Test" == "Test" & Null) ; This should be False by theory, but it is True in AutoIt
Sleep(1000) ; Sometime for you to read the result

 

Is this a bug or expected behaviour? Thanks in Advance, TD :)

EasyCodeIt - A cross-platform AutoIt implementation - Fund the development! (GitHub will double your donations for a limited time)

DcodingTheWeb Forum - Follow for updates and Join for discussion

Link to comment
Share on other sites

According to the help file keyword Null always evaluates to Null or an empty string:

"Null evaluates only to Null, still in mathematical operations this keyword has value of 0, and as string it has no value (empty string)."

So - as always - the help file is your friend ;)

My UDFs and Tutorials:

Spoiler

UDFs:
Active Directory (NEW 2022-02-19 - Version 1.6.1.0) - Download - General Help & Support - Example Scripts - Wiki
ExcelChart (2017-07-21 - Version 0.4.0.1) - Download - General Help & Support - Example Scripts
OutlookEX (2021-11-16 - Version 1.7.0.0) - Download - General Help & Support - Example Scripts - Wiki
OutlookEX_GUI (2021-04-13 - Version 1.4.0.0) - Download
Outlook Tools (2019-07-22 - Version 0.6.0.0) - Download - General Help & Support - Wiki
PowerPoint (2021-08-31 - Version 1.5.0.0) - Download - General Help & Support - Example Scripts - Wiki
Task Scheduler (NEW 2022-07-28 - Version 1.6.0.1) - Download - General Help & Support - Wiki

Standard UDFs:
Excel - Example Scripts - Wiki
Word - Wiki

Tutorials:
ADO - Wiki
WebDriver - Wiki

 

Link to comment
Share on other sites

What do you need it for? What do you expect?
Do you want to terminate a string with a null character?

My UDFs and Tutorials:

Spoiler

UDFs:
Active Directory (NEW 2022-02-19 - Version 1.6.1.0) - Download - General Help & Support - Example Scripts - Wiki
ExcelChart (2017-07-21 - Version 0.4.0.1) - Download - General Help & Support - Example Scripts
OutlookEX (2021-11-16 - Version 1.7.0.0) - Download - General Help & Support - Example Scripts - Wiki
OutlookEX_GUI (2021-04-13 - Version 1.4.0.0) - Download
Outlook Tools (2019-07-22 - Version 0.6.0.0) - Download - General Help & Support - Wiki
PowerPoint (2021-08-31 - Version 1.5.0.0) - Download - General Help & Support - Example Scripts - Wiki
Task Scheduler (NEW 2022-07-28 - Version 1.6.0.1) - Download - General Help & Support - Wiki

Standard UDFs:
Excel - Example Scripts - Wiki
Word - Wiki

Tutorials:
ADO - Wiki
WebDriver - Wiki

 

Link to comment
Share on other sites

Glad to be of service :) I always like to solve such easy challenges ;)

My UDFs and Tutorials:

Spoiler

UDFs:
Active Directory (NEW 2022-02-19 - Version 1.6.1.0) - Download - General Help & Support - Example Scripts - Wiki
ExcelChart (2017-07-21 - Version 0.4.0.1) - Download - General Help & Support - Example Scripts
OutlookEX (2021-11-16 - Version 1.7.0.0) - Download - General Help & Support - Example Scripts - Wiki
OutlookEX_GUI (2021-04-13 - Version 1.4.0.0) - Download
Outlook Tools (2019-07-22 - Version 0.6.0.0) - Download - General Help & Support - Wiki
PowerPoint (2021-08-31 - Version 1.5.0.0) - Download - General Help & Support - Example Scripts - Wiki
Task Scheduler (NEW 2022-07-28 - Version 1.6.0.1) - Download - General Help & Support - Wiki

Standard UDFs:
Excel - Example Scripts - Wiki
Word - Wiki

Tutorials:
ADO - Wiki
WebDriver - Wiki

 

Link to comment
Share on other sites

Null has a broad semantic. It essentially means "I don't know" value (or rather "non value"). That's pretty formal in SQL but in AutoIt Null can get converted to some other type as Water quoted.

I believe you're confusing the Null value (keyword) with the ANSI control character NUL which is 0x00 exactly with string datatype. So you seem to want something like $sMyString &= Chr(0)

Edited by Jos
Changed Asc to Chr

This wonderful site allows debugging and testing regular expressions (many flavors available). An absolute must have in your bookmarks.
Another excellent RegExp tutorial. Don't forget downloading your copy of up-to-date pcretest.exe and pcregrep.exe here
RegExp tutorial: enough to get started
PCRE v8.33 regexp documentation latest available release and currently implemented in AutoIt beta.

SQLitespeed is another feature-rich premier SQLite manager (includes import/export). Well worth a try.
SQLite Expert (freeware Personal Edition or payware Pro version) is a very useful SQLite database manager.
An excellent eBook covering almost every aspect of SQLite3: a must-read for anyone doing serious work.
SQL tutorial (covers "generic" SQL, but most of it applies to SQLite as well)
A work-in-progress SQLite3 tutorial. Don't miss other LxyzTHW pages!
SQLite official website with full documentation (may be newer than the SQLite library that comes standard with AutoIt)

Link to comment
Share on other sites

  • Developers
Just now, TheDcoder said:

but I am a little confused

Only a little ? :)

Closing this thread to avoid 2 discussions on the same thing.

SciTE4AutoIt3 Full installer Download page   - Beta files       Read before posting     How to post scriptsource   Forum etiquette  Forum Rules 
 
Live for the present,
Dream of the future,
Learn from the past.
  :)

Link to comment
Share on other sites

  • Jos locked this topic
Guest
This topic is now closed to further replies.
 Share

×
×
  • Create New...