Drop char var based on length

[frakje]

Hallo once again

I have an ID variable called “CPR” which must be 10 characters long. 

Its a char var with numbers. 

I want to drop those observations who doesn’t meet this criteria. 

My code look like this: 

date have; 

set want; 

if lengthn(cpr) <10 then drop;

run; 

can anyone help ?

kind regards Frank 

[Kurt_Bremser · Accepted solution]

Drop is a declarative statement that can't be executed conditionally, as it is meant to alter the data structure.

If you want to get rid of observattons with faulty entries, use a where condition, a subsetting if, or a conditional delete:

/* method with where */
date have; 
set want; 
where lengthn(cpr) ge 10;
run;

/* subsetting if */
date have; 
set want; 
if lengthn(cpr) ge 10;
run;

/* delete */
date have; 
set want; 
if lengthn(cpr) < 10 then delete;
run;

The most performant of these three is the where.

[Astounding]

In real life, data mistakes come in all shapes and sizes.  

There might be leading blanks.

There might be letters mixed in with the numbers.

There might be values that are longer than 10 characters.

If you want to keep observations that have exactly 10 digits, consider:

if length(compress(cpr, , 'kd') ) = 10;