Proc informat using cntlin option - sas

Question

I am trying to make character informat from the range values given in a dataset.
Dataset : Grade
Start End Label Fmtname Type
0 20 A $grad I
21 40 B $grad I
41 60 C $grad I
61 80 D $grad I
81 100 E $grad I
And here is the code i wrote to create the informat
proc format cntlin = grade;
run;
And now the code to create a temp dataset using the new informat
data temp;
input grade : $grad. ## ;
datalines;
21 30 0 45 10
;
The output i wanted was a dataset Temp with values :
Grade
A
B
A
..
Whereas the dataset Temp has values :
Grade
21
30
0
...
SAS Log Entry :
1146 proc format cntlin = grade;
NOTE: Informat $GRAD has been output.
1147 run;
NOTE: PROCEDURE FORMAT used (Total process time):
real time 0.01 seconds
cpu time 0.01 seconds
NOTE: There were 5 observations read from the data set WORK.GRADE.
1148
1149
1150 data temp;
1151 input grade : $grad. ## ;
1152
1153 datalines;
NOTE: SAS went to a new line when INPUT statement reached past the end of a
line.
NOTE: The data set WORK.TEMP has 5 observations and 1 variables.
NOTE: DATA statement used (Total process time):
real time 0.03 seconds
cpu time 0.03 seconds
I am not able to understand why informat is not working. Can anyone please
explain where i am making my mistake.

Answer 1

INFORMATS convert characters to (characters or numbers). So you can't use START/END the way you are doing so, since that only works with numbers.
See the following:
proc format;
invalue $grade
'0'-'20'="A"
'21'-'40'="B"
'41'-'60'="C"
'61'-'80'="D"
'81'-'100'="E";
quit;
proc format;
invalue $grade
'21'='A';
quit;
The latter works, the former gives you an error. So, you could write a dataset with all 101 values (each on a line with START), or just write a format and do it in a second step (read in as a number and then PUT to the format).