title: How to hide or disable in-function printed message
body: <p>Suppose I have a function such as:</p>
  
  <pre><code>ff &lt;- function(x) {
    cat(x, "\n")
    x^2}
  </code></pre>
  
  <p>And run it by:</p>
  
  <pre><code>y &lt;- ff(5)
  # 5 
  y
  # [1] 25
  </code></pre>
  
  <p>My question is how to disable or hide the <code>5</code> printed from <code>cat(x, "\n")</code> such as:</p>
  
  <pre><code>y &lt;- ff(5)
  y
  # [1] 25
  </code></pre>