What is the length range for numeric and character vars in SAS?

[cosmid]

Hi,

For numeric, the default is 8 bytes.

Question 1.: What is the range? When I google this, I see some place say it's 2-8 and some place say it's 3-8?

Question 2: What happens when you need a numeric var to store more than 8 bytes?

For character, the range is 1 to 32,767 bytes.

Question 3: The default size for character var is also 8 bytes?

[Tom · Accepted solution]

The minimum length you can use to store a numeric variable varies based on the hardware being used.  If you are using an IBM mainframe then you can store only 2 bytes.  But if you are using other hardware you must store at least 3 bytes.  This is because of differences between the floating point representations used by the two.

You cannot store numbers using more than 8 bytes.  SAS uses 64 bit floating point numbers.  It only take 8 bytes to store 64 bits.  This also means there is a limit on the maximum number of digits of precision that you can store.

If you do not DEFINE the storage length for your variables then SAS is forced to GUESS what length to use.  It does this based on the information that is available at the point when it must define the length.  For example if the first place you reference a character variable is in an assignment statement it will set the length to match the length of the value being assigned. If the first place it is referenced is when it is associated with a format or an informat then it will set the length based on the width of the format or informat being used. If there is no other clue about how to define the length it will use 8.  For example if the first place the variable SEX appears is in the input statement:

input id sex $ ;

SAS will decide that SEX should be character because of the $ modifier on the INPUT statement.  But since there is no column numbers or informat specified that could help if guess how long to make it then it will just make it a length of 8.

[cosmid]

Thank you!