title: Ruby IF no ARGV given
body: <p>This is my code:</p>
  
  <pre><code>if ARGV[0] == false
      puts "Usage: ./script.rb argument"
      exit
  end
  print "Yey we got an argument: " ARGV[0]
  </code></pre>
  
  <p>But I just cant make the code check if ARGV[0] is given or not, how should I do that ? </p>