Select tag - uses the default text as a placeholder prompt but is not considered a valid value

select label - Use the default text as a placeholder prompt but not as a valid value

Graphic effect ：

The code snippet is as follows ： 

<select>
        <option value="" selected disabled hidden> Please select a city you have been to </option>
        <option value="1"> Beijing </option>
        <option value="2"> Shanghai </option>
        <option value="3"> Guangzhou </option>
        <option value="4"> Chengdu </option>
      </select>

Here's the point ：

stay option Add on label selected disabled hidden attribute