- htmlspecialchars: documentation ( source)
<?php
//example data from db:
$user = ['store_id' => '99', 'store_name' => 'konrados'];
//easier way to output it:
echo "<option value = '{$user['store_id']}'>{$user['store_name']}</option>";
// easier easier way
?>
<option value="<?= $user['store_id'] ?>"><?= $user['store_name'] ?></option>
<?php
// easier easier way with no XSS risk
?>
<option value="<?= (int) $user['store_id'] ?>"><?= htmlspecialchars($user['store_name']) ?></option>