topic statement between outer and inner %do loop in SAS Programming

statement between outer and inner %do loop

SAS_inquisitive — Sun, 04 Jun 2017 03:27:22 GMT

Hello,

I was trying to understand how does the statements between outer and inner %do loop work as this psuedo code.

%macro mac;

................;

%do i = 1 %to m;

statement ;

%do j = 1 %to n;

.................;

%end;

...............;

%mend mac;

Re: statement between outer and inner %do loop

Astounding — Sun, 04 Jun 2017 03:44:25 GMT

You're mixing DATA step code and macro language code in a way that will never run. Macro language does not understand that "m" or "n" is a variable in a data set. If you were to correct that by hard-coding a value like 3 or 5 instead of m or n, what happens depends on what the statement is. If it is a macro language statement, it executes for each value of &i, after which the inner loop executes. However, if statement is a DATA step statement (or some other form of SAS code), it gets added to your program as a statement to be executed, for each value of &i. After each addition, the inner loop runs.

Mixing DATA step code and macro language code is a common mistake, but without a more specific example it's not possible to guide you in the right direction.

Re: statement between outer and inner %do loop

Tom — Sun, 04 Jun 2017 03:47:21 GMT

In your example the macro won't generate anything since N and M are not numbers. I suspect that you meant to use &M and &N instead as the upper bounds for your %DO loops.

In that case it will generate "statement;" &M times and it will generate the "....;....." statements inside the inner loop &M*&N times.

Re: statement between outer and inner %do loop

Reeza — Sun, 04 Jun 2017 05:07:39 GMT

Run it, put unique %PUT statements at each level to trace it. Always learn how to trace your code mentally and practically. It's faster to test.

Re: statement between outer and inner %do loop

SAS_inquisitive — Sun, 04 Jun 2017 15:11:38 GMT

Yes. I meant &m and &n. Thank you all.