title: NoMethodError: undefined method `match?' for "Ruby":String
body: <p>I'm trying to check whether input from user matches RegEx <code>[a-zA-z]</code> so I've checked the docs for proper method. I found <code>match?</code> in <a href="http://ruby-doc.org/core-2.4.0/String.html#method-i-match-3F" rel="noreferrer">Ruby-doc.org</a> and copied the example shown in docs to irb, but instead of <code>true</code> I'm getting this:</p>
  
  <pre><code>2.3.3 :001 &gt; "Ruby".match?(/R.../) 
  NoMethodError: undefined method `match?' for "Ruby":String
  Did you mean?  match
          from (irb):1
          from /usr/local/rvm/rubies/ruby-2.3.3/bin/irb:11:in `&lt;main&gt;'
  </code></pre>
  
  <p>Why this method doesn't work in my irb?</p>