making a select element a dropdown code example

Example 1: number dropdown html

<select id="selectNumber">
  <option value="1">One</option>
  <option value="2">Two</option>
  <option value="3">Three</option>
</select>

Example 2: options in html

<form id="form">
            <label for=""></label>
            <br>
            <input type="" id="">
            <br>
            <label for=""></label>
            <br>
            <input list="browsers" name="Thenicknamey" id="Thenickname">
            <datalist id="browsers">
                <option value=""></option>
                <option value=""></option>
                <option value=""></option>
            </datalist>
            <br>
            <label for=""></label>
            <br>
            <input type="" id="">
            <br>
            <input type="" id="">
        </form>