title: How to make sure user enters allowed enum
body: <p>I have to write a program with an Enum state, which is the 50 2-letter state abbreviations(NY, FL, etc). I need to make a program that asks for the user info and they user needs to type in the 2 letters corresponding to the state. How can I check that their input is valid i.e matches a 2 letter state defined in Enum State{AL,...,WY}? I suppose I could make one huge if statement checking if input == "AL" || ... || input == "WY" {do stuff} else{ error input does not match state }, but having to do that for all 50 states would get a bit ridiculous. Is there an easier way to do this?</p>
  
  <p>Also if Enum State is defined as {AL, NY, FL}, how could I cast a user input, which would be a string, into a State? If I changed the States to {"AL", "NY", "FL"} would that be easier or is there another way to do it?</p>