Calculating the length of a string within a variable SAS

Question

I have imported some data into SAS through SQL. I want to change the length of the variables to improve the efficiency and storage of the dataset, however I don't know what the maximum length of the variable should be.

For example I have the variable "Forename". It's length is currently set to $300. I know this is too large but don't want to take a guess at what it should be in case I chop off any data. If I have the following names, how can I work out that I need to reset the length to $10.?:

Obs Forename    Total Character Length
1   Tim         3
2   Gary        4
3   Samantha    8
4   Christopher 10

Answer 1

This isn't really a dynamic answer but it's pretty simple. Just get the maximum length of the Forename variable.

proc sql;
select max(length(forename)) from have;
quit;

This will just return the max length then you can plug it into the following data step.

data want;
length forename $11;
set have;
run;