title: Replacing pattern in R using gsub
body: <p>I am having an issue in replacing <code>opp</code> with <code>opportunity</code></p>
  
  <p>using the below code , it works well; however when there is <code>opportunity</code> as a word it gets replaced by <code>opportunityortunity</code></p>
  
  <p>How to solve this issue</p>
  
  <pre><code>data &lt;- c("opp", "opportunity")
  
  gsub("opp", "opportunity", data)
  </code></pre>