title: Iterate through Data tables and remove the columns in the List
body: <p>I have a <code>List&lt;String&gt;</code> that has allowed columns. and I have a dataset DT1 which has all the columns listed . Now that i want to do is to only get allowed columns from DT1.</p>
  
  <pre><code>List&lt;String&gt; = FirstName,LastName,Age,EmailAddress
  DT1 contains = FirstName,LastName,Age,EmailAddress,Sex,PhoneNumber,Address
  </code></pre>
  
  <p>I have already tried <code>DataTable.Merge()</code> , <code>foreach</code> etc... but i couldn't get my expected result.</p>