JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="input" cols="30" rows="10">1;Option 1
2;Option 2
3;Option 3</textarea>
<br />
<input type="button" value="Parse" onclick="parseIt();" />
<select name="" id="vals" style="display: none;"></select>

JavaScript

function parseIt()
{
    splitValues = document.getElementById("input").value.split("\n");
    if (splitValues.length > 0)
    {
        document.getElementById("vals").style.display = 'inline';
        console.log(splitValues);
        for (i = 0; i < splitValues.length; i++)
            document.getElementById("vals").innerHTML += '<option value="' + splitValues[i].split(",")[1] + '">' + splitValues[i].split(",")[0] + '</option>';
    }
}