topic Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value in SAS Programming

how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Tue, 23 Jun 2020 12:13:34 GMT

%let i=1 ;

%let or1=europe ;

%let europe1=germany ;

%let europe_germany1=berlin ;

%let europe_germany_berlin1=capital ;

/*first*/

%put &&or&i ; /*europe*/

/*second*/

%put &&&&&&or&i..&i ; /*germany */

/*third*/

%put &&&&&&&&&&or&i.._&&&&&&or&i..&i..&i ; /*berlin*/

/*fourth*/

%put &&&&&&&&&&&&&&&&&&or&i.._&&&&&&or&i..&i.._&&&&&&&&&&or&i.._&&&&&&or&i..&i ; /*not coming*/

If I run above 4 steps 3 steps coming correctly and fourth one not resolving .

How many ampersands should I keep to get value 'capacity' .

And one more question how to count to keep particular ampersands for fourth step .

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

mkeintz — Tue, 23 Jun 2020 13:21:22 GMT

I suggest the statement

OPTIONS SYMBOLGEN

to get a report on how the macro processor is parsing your macro expressions.

You can then track step-by-step how it's being interpreted. Remember that the macro parses the expression iteratively. I.e. a each (disjoint) && becomes & from left to right. Then the process starts again at the left end of the expression.

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Tue, 23 Jun 2020 13:24:11 GMT

thank you and who to get capital value please give code

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

AhmedAl_Attar — Tue, 23 Jun 2020 13:32:46 GMT

@thanikondharish

To simplify the code for everyone (You & others looking at your code), I would do it this way

%let i=1 ;
%let or1=europe ;
%let europe1=germany ;
%let europe_germany1=berlin ;
%let europe_germany_berlin1=capital ;

%let continent =%superq(or&i);
%let country=%superq(%str(&&or&i)&i);
%let city=%superq(%upcase(&continent%str(_)&country&i));
%let city_type=%superq(%upcase(&continent%str(_)&country%str(_)&city&i));
%put &continent &country &city &city_type;

Hope this helps,

Ahmed

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Tue, 23 Jun 2020 13:37:11 GMT

thank you and can we do like see my coding fourth step almost 3 steps came
and fourth one how to get value 'capital'

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

AhmedAl_Attar — Tue, 23 Jun 2020 13:43:38 GMT

I see your original code, and honestly, If I inherited your code, I would re-write it, as it's not maintainable, and I would not attach my name to code that looks like that.

Sorry for being bluntly honest.
Ahmed

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

Tom — Tue, 23 Jun 2020 14:12:46 GMT

https://www.amazon.com/Doctor-hurts-when-Jokes-Cartoons/dp/150043230X

It is not worth it to figure that out. Build the name in pieces using multiple macro variables and multiple %LET statements.

Or better still don't store data in macro variables. Explain what problem you are trying to solve by storing data into macro variables with numeric suffixes on the end of the macro variable names. I am sure there is a way to solve the problem that does not need to use such a complex storage system.

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Tue, 23 Jun 2020 14:16:11 GMT

I need value capital without using macro variable europe_germany_berlin1

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

Tom — Tue, 23 Jun 2020 14:24:37 GMT

@thanikondharish wrote:
I need value capital without using macro variable europe_germany_berlin1

So where is the value CAPITAL stored? In your example is was in the macro variable EUROPE_GERMANY_BERLIN1.

%let europe_germany_berlin1=capital ;

Do you have it stored somewhere else?

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

Oligolas — Tue, 23 Jun 2020 19:39:42 GMT

Hi,

knowing the result, I used a brute force method to find exactly what you were looking for.

If you want undebugable crappy code that almost looks like a reverse encrypted md5 checksum try this 😂:

%put &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&or&i.._&&&&&&or&i..&i.._&&&&&&&&&&or&i.._&&&&&&or&i..&i..&i..&i.; /*capital*/

More seriously, take a look at @AhmedAl_Attar 's clean little piece of code

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

ballardw — Tue, 23 Jun 2020 20:05:57 GMT

If you are attempting to do some sort of look up from one value to another perhaps a format is the way to accomplish this. If this data does not change often then you may find this easier that something attempting to use that many indirect macro references.

proc format;
Value $capital
"GERMANY"="Berlin"
"FRANCE" ="Paris";
run;


%let country=germany;
%let capital = %sysfunc(putc(%upcase(&country.),$capital.));
%put capital is &capital.;

One of the things that makes formats powerful is a single place to change things. If a new country gets added modify the code (or the data set that could generate the format) and execute the proc format code. If the format is placed in a permanent library and the format search path then the current format is always available.

proc format;
Value $capital
"GERMANY"="Berlin"
"FRANCE" ="Paris"
"NEWPLACE" = "Some City";
;
run;


%let country=newplace;
%let capital = %sysfunc(putc(%upcase(&country.),$capital.));
%put capital is &capital.;

for example to add to the format.

The %UPCASE in the PUTC is used because the value comparison done by Proc Format values is case sensitive by default and use of %upcase will result in one value to search for.

I strongly suspect the whole approach is poor at best, hence the origin of the question.

I've only been programming in SAS off and on for 33 years. I have used an indirect reference macro variable with &&& maybe 4 times. And after reconsidering it usually indicated I should use a different approach to creating the values needed.

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Wed, 24 Jun 2020 06:33:11 GMT

thank you it working I have tried with 22 and 24 ampersands in your code
almost
around 64 ampersands how did you keep this much of ampersands ,How did you
calculate .
symbelgen is just how resolving the macro variable

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

Oligolas — Wed, 24 Jun 2020 08:23:40 GMT

Hi,

"brute force" means I tried adding ampersands until I get the result.

I redirected the output to an external log file (>400MB) and searched the syntax issuying 'capital' in the output 😎

Re-think your code if you ever need more than 2 consecutives ampersands

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

thanikondharish — Wed, 24 Jun 2020 08:26:12 GMT

Thank you

Re: how to solve macro and how many put ampersands should I keep in macro variable for get the value

ChrisNZ — Wed, 24 Jun 2020 09:09:57 GMT

> it working I have tried with 22 and 24 ampersands in your code almost around 64 ampersands how did you keep this much of ampersands

If you wrote code like this you'd be fired. It's impossible to read.