title: How to escape the symbol of percentage '%' in r?
body: <p>In an url, I am dealing with the special character '<strong>%</strong>' that I should pass as a string. The url contain some argumnents so I use <code>sprintf.</code> How to escape the symbol '<strong>%</strong>' in r ?</p>
  
  <pre><code>start &lt;- 1
  #%s is my variable
  url&lt;-(sprintf('https://www.amazon.com/s/ref=sr_pg_%s?rh=n%3A172282%2Cn%3A%21493964%2Cn%3A502394%2Cn%3A281052%2Cn%3A12556502011%2Cn%3A3017941&amp;page=%s&amp;ie=UTF8', start, start))
  </code></pre>
  
  <blockquote>
    <p>invalid format '%2Cn%3A'; use format %s for character objects</p>
  </blockquote>