How do I do String comparison in Ruby? [duplicate]

This question already has answers here: Ruby: String Comparison Issues (5 answers) Closed 3 years ago.

I am using the following code to compare strings but it always takes me to the else. Why?

print("Enter your state abbreviation: ")
state_abbreviation = gets
if state_abbreviation.upcase == "NC"
  puts("North Carolina")
elsif state_abbreviation.upcase == "SC"
  puts("Sourth Carolina")
elsif state_abbreviation.upcase == "GA"
  puts("Georgia")
elsif state_abbreviation.upcase == "FL"
  puts("Florida")
elsif state_abbreviation.upcase == "AL"
  puts("Alabama")
else
  puts("You have enter wrong abbreviation")
end

I also have tried .eql?开发者_JAVA技巧("string") but I get the same result.

---

The string returned by gets will have a linebreak at the end. Use String#chomp to remove it (i.e. state_abbreviation = gets.chomp).

PS: Your code would look much cleaner (IMHO) if you used case-when instead of if-elsif-elsif.

---

I don't have enough points to comment, but I think the hash idea by Chris Jester-Young is really neat.

statehash = { "RI" => "Rhode Island", "NC" => "North Carolina" }

print "Enter your state abbreviation: "
state_abbreviation = gets.chomp.upcase

puts statehash[state_abbreviation]

this code is a lot more concise and clear than a bunch of elsif and shorter than a case. It also allows for a hash of state objects, where the key is the abbreviation and the value is the object.

---

Before the big block, say:

state_abbreviation.chomp!

As an alternative to sepp2k's excellent suggestion to use case, consider making a hash with the state abbreviations as keys.

---

gets returns what you typed with a newline. Try state_abbreviation = gets.chomp

---

You are using gets, and probably your shell/input is adding a newline (\n) character at the end of the string, and maybe you may want to use the case statement:

example:

print("Enter your state abbreviation: ") 
state_abbreviation = gets.strip

case state_abbreviation
  when "NC" then puts("North Carolina")
  when "SC" then puts("South Carolina")
  # ...
  else puts("You have enter wrong abbreviation")
end

---

While we're off topic and commenting on the approach vs. the problem, check out this rails cast. He pulls in all the state abbreviations from a website. I'm a fan of this because it gets the mappings out of your code entirely (though might be a good idea to save the site, just in case). You could then put that together with a cache to prevent actually hitting the DB.

http://railscasts.com/episodes/179-seed-data

http://railscasts.com/episodes/115-caching-in-rails-2-1