Zugg Software :: View topic

Posted: Sun Nov 10, 2002 1:26 am

Hello

1.
Which of the following is correct? My question is when should I be using %eval, and when not?

#IF (@hp>%eval(@maxhp-50)) {#NOOP}
#IF (@hp>(@maxhp-50)) {#NOOP}

2.
How should you declare a variable to be false, if you're being technically correct?

#VARIABLE myvar FALSE
#VARIABLE myvar 0
#VARIABLE myvar ""
#VARIABLE myvar {}

3.
If you are working with variables which are specific to a particular script, is it OK to undeclare them when the script finishes, even though the script runs very regularly (ie. every 2 seconds), or will this eventually cause Zmud to have memory allocation errors? I like to keep my variables all in the same class folder so I can find them easily, and when I'm examining/editing my scripts, I don't want to sift through too many unimportant variables.

#UNVAR myvar

Thanks,
Steve ;)

MASTER Joined: 28 Nov 2000 Posts: 4817 Location: USA

1. They both work. The first parameter to #IF is an expression, zMUD automatically evaluates it. You don't need to use %eval, but it won't hurt anything if you do.
This took about a minute to test, I'm a slow typer.

2. Depends on what else you intend to do with the variable. If it's just being used to track a true/false state I prefer 1 for true and 0 for false. If I'm planning to use the variable to concatenate strings or as an item list or record variable, I'd probably use a null string for false. Three common ways of assigning null strings are:
#VAR myvar ""
#VAR myvar {}
#VAR myvar %null
They all work identically, which you use is a matter of personal preference.
I haven't had much success with on/off, true/false, yes/no, but I haven't made any effort to use them other than for testing.

Personally, I don't really care very much about what's "technically correct", I'm much more interested in "what works?".

3. I haven't had any problem with removing variables, however I don't do it on a wholesale basis the way you're suggesting. I suspect you'll have to be the one to provide the answer to this question.

LightBulb
Senior Member

Posted: Sun Nov 10, 2002 2:04 am

Thanks Lightbulb

One further question, because the %eval function exists, I presume that some commands in Zmud automatically evaluate and some don't. Do you know any of the obvious ones?

Thanks,
Steve ;)

MASTER Joined: 28 Nov 2000 Posts: 4817 Location: USA

From the helpfile topic Advanced Topics, subtopic Advanced Programming:

{quote}
When commands are executed, the type of each parameter determines whether the parameter will be expanded, evaluation, or left alone. For nitty-gritty details of the zMUD Programming syntax, read the zMUD Programming Language Manual on the web at http://www.zuggsoft.com/zmud/prog.htm .
For example, the #VAR command takes a String parameter, which is expanded, so

#VAR temp 5 assigns the number 5 to the variable temp

#VAR hp {100/@temp}

#SHOW @hp displays 100/5

However, the #MATH command takes an Expression which is evaluated, so

#VAR temp 5 assigns the number 5 to the variable temp

#MATH hp 100/@temp

#SHOW @hp displays 20

The #FUNC command takes a Literal which is left alone, so

#VAR temp 5 assigns the number 5 to the variable temp

#FUNC hp 100/@temp

#SHOW @hp displays 100/@temp
{end quote}

I'd strongly recommend you look at the website mentioned.

LightBulb
Senior Member

Posted: Sun Nov 10, 2002 2:45 am

Thankyou LightBulb - I will definately take a look there.

Steve :)