SAS colon format modifier - sas

Question

What do the numbers in the grey box represent? And what's a simple way of understanding how the colon modifier affects the way sas reads in values?

Answer 1

The answer depends on information not provided. The answer B is the best choice in the sense that you should use the colon modifier when using informats in the INPUT statement to prevent the use of the formatted input mode instead of list input mode. Otherwise the formatted input could read too many or too few characters and also might leave the cursor in the wrong place for reading the next field.
But if you try to read that data from in-line cards it works fine for those two lines. That is because in-line data lines are padded to next multiple of 80 bytes.
If you put those lines into a file without any trailing spaces on the lines then the second line fails because there are not 10 characters to read for the last field. But if you add the TRUNCOVER option (or PAD) to the INFILE statement then it will work.
Try it yourself. TEST1 and TEST3 work. TEST2 gets a LOST CARD note.
data test1;
input name $ hired date9. age state $ salary comma10.;
format hired date9.;
cards;
Donny 5MAR2008 25 FL $43,123.50
Margaret 20FEB2008 43 NC 65,150
;
options parmcards=test;
filename test temp ;
parmcards;
Donny 5MAR2008 25 FL $43,123.50
Margaret 20FEB2008 43 NC 65,150
;
data test2;
infile test;
input name $ hired date9. age state $ salary comma10.;
format hired date9.;
run;
data test3;
infile test truncover;
input name $ hired date9. age state $ salary comma10.;
format hired date9.;
run;
With different data the first formatted input can cause trouble also. For example if the date values used only 2 digits for the year it would throw things off. So it tries to read FL as the age and then reads the first 8 characters of the salary as the STATE and just blanks as the SALARY.
data test1;
input name $ hired date9. age state $ salary comma10.;
format hired date9.;
cards;
Donny 5MAR08 25 FL $43,123.50
Margaret 20FEB2008 43 NC 65,150
;
Results:
Obs name hired age state salary
1 Donny 05MAR2008 . $43,123. .
2 Margaret 20FEB2008 43 NC 65150