<?php
   
  $str="Railway-List, Bank-List1, Bank-List2, Education, Ecommerce, Articles, Railway-List1";
  $findme="bank";
  $tokens= explode(",", $str);
  for($i=0;$i<count($tokens);$i++)
  {
    $trimmed =trim($tokens[$i]);
	$pos = stristr($trimmed, $findme);
	if ($pos === false) {}
	else
	{
		echo $trimmed.",";
	}
  }
?>