<?php
while($row=mysqli_fetch_array($res))
    {
?>
     <a href="http://localhost/profileviews/view.php?name=<?php echo $row["username"]; ?>"><?php echo $row['username']; ?></a>
<?php
    }
?>

while($row=mysqli_fetch_array($res))
{
  echo'<a href="http://localhost/profileviews/view.php?name='.$row['username'].'">'.$row['username'].'</a>
}

while($row=mysqli_fetch_array($res))
{
    $username = $row['username'];
    echo "<a href='http://localhost/profileviews/view.php?name=$username'>$username</a>";
}