#Writing sas code code#
#Writing sas code series#

If you write a semi-colon in the middle of a sentence for grammatical reasons, then SAS will interpret this as the end of a comment, and will try to interpret the rest of your comment as valid SAS code. The one thing you need to watch out for using this style of commenting is your use of semi-colons.

#Writing sas code code#

This way, all of your co-workersВ can read what your code is trying to do without actually reading the program. Writing descriptions such as these is a good standard practice when you are working on a team.

Because SAS will interpret everything after the asterisk as a comment, we are able to write a short description of the program that spans multiple lines. Perhaps the most important comment in this program is the one at the top. Using comments, we are now able to describe each step of the code. * Review Flag variables with frequencies * Extract numeric variables into a dataset ДЄrray nm (*) _NUMERIC_ * All numeric variables in the dataset ДЄrray fg (*) f1 вЂ“ f&varcount * Initialize flag variablesВ as missing

#Writing sas code series#

The program has 4 general steps:ДЎ) Extract numeric variables using the contents procedureДў) Create a macro variable for the number of numeric variablesДЈ) Create a series of flag variables using the macro variableД¤) Run frequencies on all of the flags. This program checks for missing values on all numeric Using the first style, we will initiateВ a comment withВ an asterisk and end with a semi-colon.В This means that SAS will ignore everything after the asterisk until it hits the semi-colon. We can comment a program out using one of two commentingВ styles. While you may not understand each line of code, you should be able to understandВ what theВ code is doingВ if we comment it out. This is some general code I use to check for missing values on numeric variables. Proc contents data = mog out=vars (keep = name type where=(type=1)) run Options linesize = 120 pagesize = 1000 mprint To demonstrate the importance of commenting, letвЂ™s take a look at the uncommented program below.

Comments in a SAS programВ areВ essentially notes thatВ you write into the program to remind yourself (and inform others) what the code is doing.В The code interpreter built intoВ SASВ ignores the comments and will not process them asВ SAS statements.В In many cases,В a wellВ commentedВ program requires no additional documentation. SAS comments can help you avoid problems and headachesВ such as these. In the second case, many programmers have trouble following code that they wrote without some kind of reminder of what they were trying to do. In the first case, even if you are able to understand any given line of code, the sheer amount of code will be too overwhelming to understand in itвЂ™s entirety.

You start on a fairly complex program that you are unable to finish, and the revisit it some time later.

You start on a project and a co-worker hands you off a program that isВ thousands of lines long with no documentation.

There are occasions, however, when the intent of a program will not be clear and you will not understand the code.В Consider the following examplesВ (both of which have happened to me): This means that if you know a thing or two about SAS, then you do not need me to explain the purpose of the sample program, or what the individual lines of code are doing. Most of the beginner to intermediate level programs on this blog are fairly simple and self-contained.