Answers for "how to get the option list from the select html"

javascript get all select options

var options = document.getElementById('mySelectID').options;
for (let i = 0; i < options.length; i++) { 
  console.log(options[i].value);//log the value
}

html select list

<label for="cars">Choose a car:</label>

<select id="cars">
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>