Ruby intro

1. input

print "What's your first name?"
first_name = gets.chomp

　　chomp will delete " " from the string

http://www.ruby-doc.org/docs/Tutorial/part_02/user_input.html

2. output

with format #{variable_name}

first_name = "Kevin"
puts "Your name is #{first_name}!"

city = gets.chomp  
puts "The city is " + city  

3. exclaimation mark !

　　make value contain in the variable itself

state.upcase!

same as

state=state.upcase