Description: A tutorial on proper use of ! in code.

! Tutorial

I've noticed with people's scripts/addons that the ! switch is either overused, or not used at all.

It may be people's scripting style, but believe me ! in if's and commands works faster and is a lot cleaner.

First off, lets give the ! function a definition..
The ! function tells if a variable or identifier returns $null or 0. This is the big thing people miss, they believe ! is just like == $null, I repeat it is not.

When dealing with numbers and 0 the ! function may mess up any processing...
Sometimes it is safer to use != $null or == $null, just in case the user specifies 0.
It is safe to use the ! function when you know the result is either 0 or 1, $null or value, but when $null and 0 may combine, you should not use the ! function.

Let me give you some examples..


; ! Example -- /inputbox
; Here we know %x can either be $tue, Yes button, or $false, No button
alias inputbox {
  var %x = $?!="Choose one, yes or no"
  if (%x == $true) { echo -a You said Yes! }
  if (%x == $false) { echo -a You said No! }
}


Above is a bad peace of code, for 2 reasons.. ! can establish $true and $false, and another if() isn't needed you can simply do an else.
So using the ! function and the else function we can establish a better script..

; ! Example -- /inputbox2
; The ! before %x says the same as: if (%x == $false)
alias inputbox2 {
  var %x = $?!="Choose one, yes or no"
  if (!%x) { echo -a You said No! }
  else { echo -a You said Yes! }
}

Now in if() and other comparison functions you can leave the variable alone.. Doing this is just like the ! function it will return $true if: The variable isn't null, the variable isn't $false, and if the variable isn't 0.

So if you were going to use the input box without the ! function it would look like this:

; ! Example -- /inputbox3
; Nothing before %x says the same as: if (%x == $true)
alias inputbox3 {
  var %x = $?!="Choose one, yes or no"
  if (%x) { echo -a You said Yes! }
  else { echo -a You said No! }
}


Here is a common mistake done by when radio buttons or check buttons in dialogs are being called... If the radio or check is regular and doesn’t have a 2, value then you can use the ! function...
Here would be "bad" code..

; Example of code, not to be used.
  if ($did($dname,1).state == 1) { echo -a Checked! }
  else { echo -a Unchecked! }


You could use this:

; Same as $did($dname,1).state == 1
  if ($did($dname,1)) { echo -a Checked! }
  else { echo -a Unchecked! }

or..

; Same as: $did($dname,1).state == 0
  if (!$did($dname,1)) { echo -a Unchecked! }
  else { echo -a Checked }


Note: To all, I used if()'s then else events, I do relize that use can simply do the $iif() event and save time and code.. If for some reason you do not know what i mean here is the /inputbox3 example with $iif

; $iif Example - /inputbox3
alias inputbox3 {
  var %x = $?!="Choose one, yes or no"
  echo -a You sad $iif(%x,Yes!,No!)
}



You can use ! for other things besides if() events, such as returning a character that would of been evaluated.. here is what i mean..


; ! Example -- /iam
; When using ! after $ it will return $, and not evalute it.
alias iam {
  echo -a Used with !: $!me
  echo -a Used without !: $me
}


Also, you can use ! before commands..
What the ! does before commands is makes mirc use its default internal command, just in case there is already a repeat of the command..
Lets say there was an alias like:
alias msg msg $chan ( $+ $chan $+ ): $1-

Now if that alias is present each time you message a channel it will return: (#Channel): Your Message
If you do not want that and you wish to use the default mirc command in another alias, you would use:

; ! Example -- /!msg
alias msgc {
  !msg $active $+($chr(2),$1-,$chr(2))
}

That would bold your text messaging the channel and wouldn't message with the (#Channel)


If you have any questions/comments/suggestions, don't hesitate to ask.


; ! Example -- /inputbox
; Here we know %x can either be $tue, Yes button, or $false, No button
alias inputbox {
  var %x = $?!="Choose one, yes or no"
  if (%x == $true) { echo -a You said Yes! }
  if (%x == $false) { echo -a You said No! }
}

i think you meant to type $true and not $tue

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