data import; infile datalines; input id "var-1"n $ "var'g"n $ "var % of"n; datalines; 1 d e 23 2 f g 34 3 g k 45 ;;;; proc contents data=import noprint varnum out=varlist ; proc sql noprint; select name into :mylist separated by ' ' from varlist where type = 2; proc freq data=import; tables &mylist.; run; The question is easy. How can i make this code works ? The problems are the special character inside the mylist macro variable.   thanks. ... View more

Hi,   in the Certification book (Base) i found this question:   There is no end-of-file condition when you use direct access to read data, so how can your program prevent a continuous loop? a. Do not use a POINT= variable. b. Check for an invalid value of the POINT= variable. c. Do not use an END= variable. d. Include an OUTPUT statement.   with this answer   Correct answer: b To avoid a continuous loop when using direct access, either include a STOP statement or use programming logic that executes a STOP statement when the data step encounters an invalid value of the POINT= variable. If SAS reads an invalid value of the POINT= variable, it sets the automatic variable _ERROR_ to 1. You can use this information to check for conditions that cause continuous looping.   I understand the use of STOP statement but i can't realy figure out what the "invalid value" can be used. Can someone explain better or with other words what does this answer mean ? And maybe post some example code ?   thanks, Arjuna ... View more