Lookup table

Question

I want to basically do a look up table in code, whether its array of strings , enumeration, or dictionary, im trying to find the best way.
I want to do lookup base off of the  code, so when I extact data in and I get a string that is "000", I want to say "000" is cat. which is the best way to do this

item   code

cat  , "000"
dog , "001"
mice, "01A"

Hi you guys what do you think is the best way to do this, right now my lookup table is in the database and im pulling from the database which is cool, but im trying to limit the database from doing all the work.