JSFiddle - React, Tailwind, and code Playground

HTML

<input id="test1" data-test1="100.01" />
        <select id="test2" data-test2="100.01">
            <option id="test3" selected="selected" data-test3="100.00"></option>
        </select>

JavaScript

// test option selection using data
var test3 = $("#test2 option:selected").data("test3");
alert("No decimal - test3[" + test3 + "]");

// test option selection using attr
var test3a = $("#test2 option:selected").attr("data-test3");
alert("Decimal - test3a[" + test3a + "]");

// dynamically add a select
$("body").append('<select id="test4" data-test4="40.00"><option id="test5" selected="selected" data-test5="50.00"></option></select>');

// test dynamically added method
var test4 = $("#test4 option:selected").data("test4");
alert("No value - test4[" + test4 + "]");