title: Ruby - simple way to convert the first letter of string to downcase
body: <p>Is there a simple way to convert the first letter of a string to downcase? <code>String#capitalize</code> modifies the entire string. Sure, I can remove the first letter, downcase it and then append it in the beginning. But it seems kinda silly, is there a simpler way?</p>
  
  <p>Note: I'll be dealing with only English words.</p>
  
  <p>Edit: <code>str[0] = str[0].downcase</code> doesn't work in JRuby 1.6 :(</p>
  
  <p>Edit 2: In the end I settled on this:</p>
  
  <pre><code>word = "ABC"
  first_capital_letter = word.match(/^([A-Z])/).to_s
   if(first_capital_letter)
     word = word.sub(first_capital_letter, first_capital_letter.downcase)
     puts word
  end
  </code></pre>