The Wherever Statement

Joan, John, Jane and Jerry just completed their first computer science course. They were given a letter grade of a, a b and c respectively. They want to convert their letter grades to numeric ones.

Calculate grades:
----------------------------------
|CS101|letter grade|numeric grade|
----------------------------------
|Joan | a          |             |
----------------------------------
|John | a          |             |
----------------------------------
|Jerry| c          |             |
----------------------------------
|Jane | b          |             |
----------------------------------
wherever letter grade is equal to a do:
    numeric grade = 4.0.
wherever letter grade is equal to b  do:
    numeric grade = 3.0.
wherever letter grade is equal to c  do:
    numeric grade = 2.0.
wherever letter grade is equal to d  do:
    numeric grade = 1.0.
wherever letter grade is equal to f  do:
    numeric grade = 0.0.
END.