title: how to extract last 4 characters of the string in SAS
body: <p>improved formatting,I am a bit stuck where I am not able to extract the last 4 characters of the string., when I write :-</p>
  
  <pre><code>indikan=substr(Indikation,length(Indikation)-3,4);
  </code></pre>
  
  <p>It is giving invalid argument.<br> 
  how to do this?</p>