topic Re: Default length of a numeric variable? in SAS Programming

Default length of a numeric variable?

kisumsam — Sun, 05 Jul 2020 13:39:28 GMT

Hi, I have learned that the default length of a numeric variable is 8. However, when I use the length statement on a numeric variable, it returns 12.

data test;
a = 1;
len = length(a);
run;

The result is 12:

Does anyone know why?

Thanks,

Sam

Re: Default length of a numeric variable?

RichardDeVen — Sun, 05 Jul 2020 13:52:52 GMT

LENGTH is a character function. You are asking for the character length of a numeric variable. A read of the LENGTH documentation will tell you:

If string is a numeric constant, variable, or expression (either initialized or uninitialized), SAS automatically converts the numeric value to a right-justified character string by using the BEST12. format. In this case, LENGTH returns a value of 12 and writes a note in the SAS log stating that the numeric values have been converted to character values.

Important take away.... read the log.

Re: Default length of a numeric variable?

kisumsam — Sun, 05 Jul 2020 14:02:23 GMT

Great thanks!

Re: Default length of a numeric variable?

Tom — Sun, 05 Jul 2020 14:02:27 GMT

You are comparing apples and oranges.

The LENGTH() function returns the length of a value, not the storage length of the variable. Use the VLENGTH() function to find out the defined storage length for a variable. The reason you get 12 is because the LENGTH() function works on character strings, not numbers. SAS will convert the number to a character string using the BEST12 format. So no matter what numeric value you try to pass to the LENGTH() function the answer will always be 12.