IF-THEN statement to create new variable with Date does not return with wanted Date.

[rebelde52]

Hello.

I want to use an IF-THEN statement followed by a By statement to create a new variable with a selected date given my IF-THEN statement. It seemed to select my conditions and create a new variable. However, when I do a proc print; the date I selected and my new column returns as a " . " instead of the date it originally had. 

How can I fix this? is this a formatting issue? I did do a proc contents and both the old and new date variable are NUM so I'm kind of confused on the issue. 

Below is my code and my output. 

data compare;
set combined;
if Pending='YES' then new_date_num = old_date_num;
by name;
run;

name	old_date_num	date	Pending	new_date_num
FM1	23264	9/11/2023	NO	.
FM1	23264	9/11/2023	NO	.
FM1	23264	9/11/2023	NO	.
FM1	23264	9/11/2023	NO	.
FM1	23271	9/18/2023	NO	.
FM1	.	9/11/2023	YES	.

[A_Kh]

Hi, 
Your code seems to return a valid value which is missing when pending='yes'; 

[rebelde52]

before this data step that value was actually 23264

[Tom]

I want to use an IF-THEN statement followed by a By statement 

That does not make any sense.  BY statement follow SET/MERGE/UPDATE statements in a DATA step.  Or follow the PROC statement in a PROC step.

Since for the observations where Pending='YES' have a missing value of old_date_num where do you want to get a non-missing value for new_date_num ?

Do you want to remember one of the values of new_date_num from one of the previous observations?