%let %put variables - what it does to your sas program

Question

I'm new in SAS. I'd like to know what the lines below do. Couldn't figure out what it does to the program because I didn't encounter any of the defined variables in the succeeding parts after declaration.

%let cutofftime  =%sysfunc(time());
%let currdt      = %sysfunc(putn(&cutofftime.,time5.)) ; 
%put &cutofftime. &currdt.;

Answer 1

The %let statement is used to create a macro variable.

The first statement:

%let cutofftime  =%sysfunc(time());

uses the time() function to determine the current time. It returns the current time as a numeric value which is number of seconds since midnight.

The second statement:

%let currdt      = %sysfunc(putn(&cutofftime.,time5.)) ; 

uses the PUTN() to convert the numeric time value (which Is now stored in the macro variable CUTOFFTIME) to a pretty formatted value like 22:30.

So after the two %let statements have run, you created two macro variables. Then the %PUT statement is used to write the values of the two macro variables to the log:

%put &cutofftime. &currdt.;

Using the %PUT statement to write the value of macro variables to the log is a useful way to debug macro code, in the same way that the PUT statement can be used to write the value of data step variables to the log as a data step debugging tool. When I run the code at 9:32 PM, the log shows:

3    %put &cutofftime. &currdt.;
77537.809 21:32

That said, if you're new to SAS, you should probably avoid the trying to learn the macro language at the same time as you are learning the SAS language.