How to convert numbers in a character variable to Numeric in sas - sas

Question

Can anyone help me to resolve this?
I have a very large raw dataset with a character variable that contains text strings along with numbers & dates defined in character format. Now I want to process the dataset and create a new numeric variable and populate values only when the text in the actual variable is either a number or a date value. Otherwise missing
RAWDATA:
ACTUAL_VARIABLE NEW_NUM_VARIABLE(Expected Values)
------------------ ---------------------------------
ODed on pills threw them all up - 2006
Y
1 1
5 5
ODed on pills
6 6
Less than once a week
N
N
2006-11-12 2006-11-12
Many Thanks in Advance

Answer 1

The easy way to do it (if you know the specific date format) is to use the input function.
09:27
If put(input(var,??yymmdd10.),yymmdd10.)=var then its a date!
else if input(var,best.) ne . then its a number.
Otherwiseits a character string.

Answer 2

This isn't as straightforward as it first looks, so I understand why it would be difficult to search for an answer. Just extracting a number is pretty easy, but when dates are included it becomes a bit more complicated (particularly when the format entered could change, e.g. yyyy-mm-dd, dd-mm-yyyy, dd/mm/yy etc).
One thing to note first. If you want to store the new values as a numeric field then you can't show a mix of numbers and dates. Dates are stored as numbers and formatted to show the date, but you can't apply a format at row level. Therefore I would suggest creating 2 new columns, 1 for numbers and 1 for dates.
My preferred approach is to use the anyalpha function to exclude any records with an alphabetic character, followed by the anypunct function to identify if a punctuation character exists (this should identify dates rather than just numbers). The anydtdte informat is then used to extract the date, this is a very useful informat as it reads dates stored in different ways (as per my note above).
There are clearly some caveats with this method.
If any numbers contain decimals then my method would incorrectly treat these as dates, therefore only integers will be assigned correctly.
It won't pick up dates that contain the month as words, e.g. 15-May-2015, as the anyalpha function would exclude them. They will need to contain numbers only, separated by any punctuation character.
Here's my code.
/* create initial dataset */
data have;
input actual_variable $ 50.;
datalines;
ODed on pills threw them all up - 2006
Y
1
5
ODed on pills
6
Less than once a week
N
N
2006-11-12
;
run;
/* extract dates and numbers */
data want;
set have;
if not anyalpha(actual_variable) then do; /* exclude records with an alphabetic character */
if anypunct(actual_variable) then new_date_variable = input(actual_variable,anydtdte10.); /* if a punctuation character exists then read in as a date */
else new_num_variable = input(actual_variable,best12.); /* else read in as a number */
end;
format new_date_variable yymmdd10.; /* show date field in required format */
run;