<select name="mydropdown">
        <option selected="selected">Choose one</option>
        <?php
        // A sample product array
        $products = array("Mobile", "Laptop", "Tablet", "Camera");
        
        // Iterating through the product array
        foreach($products as $item){
            echo "<option value='strtolower($item)'>$item</option>";
        }
        ?>
</select>

$array = array(
  1=>"My first option",
  2=> "My second option"
);

<select>
  <?php foreach($array as $key => $value) { ?>
    <option value="<?php echo $key ?>"><?php echo $value ?></option>
  <?php }?>
</select>