SAS - Example of an informat/convert character to numeric

SAS_example_informat.sas

/*This is an exmaple of how to create an informat for a character variable. 
It converts a character variable to a numeric one as well.

Author: F. Khurshed
Date: 2018-11-14
*/

*create format;
proc format;
invalue $ grade_fmt
'A' = 1
'B' = 2
'C' = 3
'D' = 4
other = 99;
run;

*generate sample data;
data have;
input grade $;
cards;
A
B
C
D
E
A
F
D
;
run;

*example usage
data want;
set have;
grade_num = input ( grade, $grade_fmt.);
run;