title: Spark: How to delete a specific variable from spark-shell memory namespace?
body: <p>I am using <code>spark-shell</code> and Scala. Is it possible to delete a variable from the shell's memory namespace?</p>
  
  <p>For example, if I create variables like this:</p>
  
  <pre><code>val foo = 1
  var bar = 2
  </code></pre>
  
  <p>Would it be possible to delete <code>foo</code> and <code>bar</code> from memory?</p>
  
  <p>I know that in Python (using <code>del</code>) and R (using <code>rm</code>), you can delete specific variables from the namespace (aka environment or workspace).</p>