topic Re: Value of Macro Variable in SAS Programming

Value of Macro Variable

NikitaTovey — Wed, 09 Dec 2020 04:33:55 GMT

Hello SAS Communities,

What is the value of the following macro variable NewVbl?

%LET NewVbl = 10+20;

Thank you!

Re: Value of Macro Variable

rhaley1821 — Thu, 10 Dec 2020 15:05:37 GMT

Hello!

The value of the macro variable is the value that you assign it and will remain the same until explicitly changed. Your macro variable newvbl will have a value of 10+20.

Here is a helpful link for better understanding how macros work: https://v8doc.sas.com/sashtml/macro/z1071889.htm

Re: Value of Macro Variable

andreas_lds — Wed, 09 Dec 2020 06:17:18 GMT

@rhaley1821 wrote:

Hello!

The value of the macro variable is the value that you assign it and will remain the same until explicitly changed. Your macro variable newvbl will have a value of 30.

Here is a helpful link for better understanding how macros work: https://v8doc.sas.com/sashtml/macro/z1071889.htm

No, the value is the string assigned to the variable, if you want to calculate, you have to use %eval or %sysevalf.

@NikitaTovey see maxim 4 in https://communities.sas.com/t5/SAS-Communities-Library/Maxims-of-Maximally-Efficient-SAS-Programmers/ta-p/352068

Re: Value of Macro Variable

JoshB — Wed, 09 Dec 2020 06:35:07 GMT

It is the characters you just assigned. It is 10+20

Re: Value of Macro Variable

ballardw — Wed, 09 Dec 2020 07:20:48 GMT

Some teacher seems not not explain things very well.

https://communities.sas.com/t5/SAS-Programming/Creating-a-Macro-variable/m-p/704449

There was another essentially identical question that I can't find as well.

Re: Value of Macro Variable

gamotte — Wed, 09 Dec 2020 09:44:47 GMT

Hello,

Here is an example to illustrate what @andreas_lds explained :

%let x=10+20;

data _NULL_;
y = 5 * &x. * 2; /* 5*10+20*2 */
z = 5 * %eval(&x.) *2; /* 5*30*2 */
put y=; /* 90 (50+40) not 300 (5*30*2) */ 
put z=; /* 300 */
run;