topic include a global variable in a do while loop in New SAS User

include a global variable in a do while loop

laiguanyu001 — Mon, 05 Aug 2019 13:39:07 GMT

Hi,

I have macro that looks like this:

%macro test;

%let var = 1;

%do %while (input("&var".,8.) > 0);

blablabla

%end;

%mend;

the sas log outputs required operator not found in expression input("&var".,8.) > 0
I would love some help to debug this... thanks!

Re: include a global variable in a do while loop

aaronh — Mon, 05 Aug 2019 13:42:33 GMT

I am guessing you meant to include the period inside the double quotes?

%do %while (input("&var.", 8.) > 0);

Re: include a global variable in a do while loop

Tom — Mon, 05 Aug 2019 13:49:23 GMT

Why are you comparing the letters inp... to the digit 0?

Don't you want the macro processor to compare the digit 1 to the digit 0?

%do %while (&var > 0);

Note that if VAR can take on non integer values in your loop then you will need to use %SYSEVALF() to allow comparison of strings that look like floating point numbers.

%do %while (%sysevalf(&var > 0));

Re: include a global variable in a do while loop

PaigeMiller — Mon, 05 Aug 2019 14:17:44 GMT

@laiguanyu001 wrote:

Hi,

I have macro that looks like this:

%macro test;

%let var = 1;

%do %while (input("&var".,8.) > 0);

blablabla

%end;

%mend;

the sas log outputs required operator not found in expression input("&var".,8.) > 0
I would love some help to debug this... thanks!

I don't see why you say &VAR is a global variable, as it is defined inside of %MACRO TEST

But anyway, %DO %WHILE() requires a macro variable or macro function inside the parenthesis. INPUT is not a macro function, that why you are getting the operator not found error. It's not even clear why you are using INPUT here, as you can test &VAR > 0 without the INPUT function.

%do %while (&var>0);

Re: include a global variable in a do while loop

andreas_lds — Mon, 05 Aug 2019 13:47:40 GMT

In the macro-language everything is text, except for expressions, so you can just write

%do %while (&var. > 0);

Re: include a global variable in a do while loop

Astounding — Mon, 05 Aug 2019 13:47:44 GMT

A few basic errors need to be fixed.

Macro language does not support the INPUT function. You need to use the INPUTN function instead.

To use DATA step functions in a macro language expression, you need to call the function use %SYSFUNC.

Macro language does not use quotes to identify strings. Get rid of them.

Incorporating all the changes:

%macro test;

%let var = 1;

%do %while (%sysfunc(inputn(&var.,8.)) > 0);

blablabla

%end;

%mend;

Finally, once you make those changes to correct the syntax, your loop will be an infinite loop. There better be some logic inside the loop that changes the %DO %WHILE condition from being true to being false.