title: Ruby multiple string replacement
body: <pre><code>str = "Hello☺ World☹"
  </code></pre>
  
  <p>Expected output is: </p>
  
  <pre><code>"Hello:) World:("
  </code></pre>
  
  <p>I can do this: <code>str.gsub("☺", ":)").gsub("☹", ":(")</code></p>
  
  <p>Is there any other way so that I can do this in a single function call?. Something like:</p>
  
  <pre><code>str.gsub(['s1', 's2'], ['r1', 'r2'])
  </code></pre>