topic Re: Can two words be joined into a variable name? in GDL

Can two words be joined into a variable name?

GDL Enthusiast — Thu, 26 Sep 2024 11:21:27 GMT

Hi,

I am wondering if it is possible to change the variable name on the fly, e.g when calling from a Subroutine, having the variable name part1+part2 merged together. An example would be a variable called Var_A where the prefix is added to the suffix, like Len = "Var"+"_A".

This would be great as it would allow a single subroutine to have its parameters changed easily, from _A to _C etc, especially when there are quite a few options variables and keep the code small. Is this possible or is there a better way of making a simple repeating subroutine with different variable inputs?

For a code example in 2D Script:

option1 = 1 option2 = 1 option3 = 1 Var_A = 0.010 Var_B = 0.015 Var_C = 0.020 IF option1 = 1 THEN Suffix = "_A" Len = "Var"+Suffix Offset = 0.01 Gosub "CircleTest": ENDIF IF option2 = 1 THEN Suffix = "_B" Len = "Var"+Suffix Gosub "CircleTest": ENDIF IF option3 = 1 THEN Suffix = "_C" Len = "Var"+Suffix Gosub "CircleTest": ENDIF END !************************************* "CircleTest": !Gosub Reference Circle2 0,0,Len RETURN

Ideally this should return three circles, but it comes up with an error.

Is there a way to string together the suffix to a common prefix?

Many thanks, Matt

Re: Can two words be joined into a variable name?

Barry Kelly — Tue, 06 Feb 2024 03:27:53 GMT

No you can not change variable names, there should be no need to.

All you need in this case is ...

IF option1 = 1 THEN Len = 0.010 Offset = 0.01 Gosub "CircleTest": ENDIF IF option2 = 1 THEN Len = 0.015 Gosub "CircleTest": ENDIF IF option3 = 1 THEN Len = 0.020 Gosub "CircleTest": ENDIF

I don't quite get what you are trying to do with 'option_1', 'option_2' & 'option_3' parameters, unless they are 3 separate boolean (on/off0 parameters.

So you could potentially have all 3 circles on at the same time.

If you simply want a choice of option 1, 2 or 3, then create a integer parameter called 'Option' (without the quotes) and give it a VALUES list in the parameter script.

VALUES "Options" 1, 2, 3

Then you will be able to choose only one of the circles at any one time.

Barry.

Re: Can two words be joined into a variable name?

GDL Enthusiast — Tue, 06 Feb 2024 01:31:32 GMT

Hi Barry,

Thank you so much for responding! I am trying to improve my coding skills. I see experts creating objects that are very concise in code, using subroutines. It seems pretty neat to be able to code so cleanly. I wondered if I could do it with changing variable names dynamically.

That is my answer "No you can not change variable names". Thank you again Barry and all the best, Matt

Re: Can two words be joined into a variable name?

Lingwisyer — Tue, 06 Feb 2024 01:49:10 GMT

The question is, why is there a need to change the variable name? In your example, it is redundant, hence Barry's answer. Does it not achieve what you are wanting? Is there something else you are trying to achieve?

Ling.

Re: Can two words be joined into a variable name?

GDL Enthusiast — Sun, 11 Feb 2024 00:33:56 GMT

Hi Ling,

Thank you for responding, I have seen some of your work and you are a true GDL coding artist! It would a dream to have your and Barry's level of coding skills.

My thought stemmed from reading AC GDL objects and how clean the script was written. I have found what would take me 50 lines of code, experts could write in 20 lines. Much neater and cleaner to follow. So my thinking became, how can I, without going back to university to get a programming degree, make my script concise and clean. Along those lines, I wondered if I could somehow reuse Subroutines multiple times, instead of writing the same repeating code but with variations in the variable names. An example of the logic being:

ValueListParameter 1 to 20, each with say 20 variables A to T. For that I code:

IF ValueListParameter1=1 THEN Len_ = 0.2 Ht_=0.33 Wdt_A=25 !...etc Gosub "Create Object:" ENDIF ... IF ValueListParameter20=1 THEN Len_ = 0.4 Ht_=1.33 Wdt_=58 !...etc Gosub "Create Object:" ENDIF END *********** "Create Object": Len = Len_ Ht = Ht_ Wdt = Wdt_ !...etc RETURN

The above 20 variables have suffixes A through to T say with unique values. In the Subroutine, if I could just change the variable suffix based upon the Gosub. Then the variables could all be stored cleanly at the start of the scipt, ready to be called and more easily managed.

If I could write something like this:

!List of Variable Values to lookup: Len_A = 0.2 Len_B=0.33 ... Len_T=0.43 Ht_A=58 ... Ht_T=58 Wdt_A=22 ... Wdt_T=32 !...etc IF ValueListParameter1=1 THEN Suffix="A" Gosub "Create Object": ENDIF ... IF ValueListParameter20=1 THEN Suffix="T" Gosub "Create Object": ENDIF END *********** "Create Object": Len = "Len_" + Suffix Ht = "Ht_" + Suffix Wdt = "Wdt_" + Suffix !...etc RETURN

Welcome any and all thoughts and many thanks, Matt

Re: Can two words be joined into a variable name?

Lingwisyer — Wed, 07 Feb 2024 01:33:19 GMT

... Len_ = Len_A goSUB ... Len_ = Len_B goSUB ...

Pretty sure what you were trying turns your parameter into a text type so that probably explains why it fails.

You could also play with matrices.

DIM Len[] Len[1] = 0.2 Len[2] = 0.33 ... Suffix = 1 goSUB ... CIRCLE2 = 0, 0, Len[Suffix]

Ling.

Re: Can two words be joined into a variable name?

GDL Enthusiast — Wed, 07 Feb 2024 02:09:39 GMT

Wow that is a good idea! DIM could be the way to go, I will see how I go coding, clean scripts coming up. Thank you so much Ling! Matt

Re: Can two words be joined into a variable name?

Lingwisyer — Wed, 07 Feb 2024 04:28:18 GMT

If you really wanted to, you could merge your Length (x), Width (y) and Height (z) parameters into a single two dimensional array.

Re: Can two words be joined into a variable name?

Jochen Suehlo — Wed, 07 Feb 2024 11:53:21 GMT

There are a few cases in which variables can be composed of several parts.
Example:

_wall_scale = GLOB_SCALE var = "Wall_" + STR(_wall_scale, 1, 0) MATERIAL 1 GOSUB var ! ---------------------------- E N D ----------------------------------- ! ! ---------------------------- E N D ----------------------------------- ! END ! -- END -- END -- END -- END -- END -- END -- END -- END -- END -- ! ! ---------------------------- E N D ----------------------------------- ! ! ---------------------------- E N D ----------------------------------- ! "Wall_200": BLOCK 1, 1, 1 RETURN ! ---------------------------------------------------------------------- ! ! ---------------------------------------------------------------------- ! "Wall_100": BLOCK 1, 2, 3 RETURN ! ---------------------------------------------------------------------- ! ! ---------------------------------------------------------------------- ! "Wall_50": BLOCK 1, 4, 9 RETURN ! ---------------------------------------------------------------------- ! ! ---------------------------------------------------------------------- !

Re: Can two words be joined into a variable name?

Lingwisyer — Thu, 08 Feb 2024 03:42:50 GMT

The difference is that GOSUB is expecting a text string, which is what var is being defined as, whilst CIRCLE2 is expecting a numeric string or numberic parameter?

Re: Can two words be joined into a variable name?

Jochen Suehlo — Thu, 08 Feb 2024 09:20:10 GMT

You can even use:
GOSUB 1000 + GLOB_SCALE
END
1050:
RETURN

I think the difference is, that with CIRCLE2 there should be the Variable name composed with different parts, while in my examples the Value of the variables are composed of different parts.
I am sorry for the confusion.

Re: Can two words be joined into a variable name?

Barry Kelly — Thu, 08 Feb 2024 09:30:49 GMT

But the original poster wanted to join two strings together to change the variable name, not the variable value.

So I think this is going a bit off topic, although it is good to know these techniques.

Barry.

Re: Can two words be joined into a variable name?

Jochen Suehlo — Thu, 08 Feb 2024 11:26:12 GMT

There are actually also situations in which the variable name can consist of compound parts; namely in cases in which a variable or a parameter name within a GDL command is to be used as a string with quotation marks.
Example:

! Parameter 1 = qay_1, Parameter 2 = qay_2 UI_INFIELD "qay_" + STR(1, 1, 0), 20, 20, 100 , 20 UI_INFIELD "qay_" + STR(2, 1, 0), 20, 50, 100 , 20