JSFiddle - React, Tailwind, and code Playground

by sparkhill

HTML

<select id="firstSelect">
   <option value="0" selected="selected">Choose...</option>
   <option value="value1">Value1</option>
   <option value="value2">Value2</option>
   <option value="value3">Value3</option>
</select>

<select id="secondSelect">
   <option value="0" selected="selected">Choose...</option>
   <option class="conditional value1" value="subValue1">Value1: Sub1</option>
   <option class="conditional value2" value="subValue2">Value2: Sub1</option>
   <option class="conditional value2" value="subValue3">Value2: Sub2</option>
   <option class="conditional value2" value="subValue4">Value2: Sub3</option>
   <option class="conditional value2" value="subValue5">Value2: Sub4</option>
   <option class="conditional value2" value="subValue6">Value2: Sub5</option>
   <option class="conditional value3" value="subValue7">Value3: Sub1</option>
   <option class="conditional value3" value="subValue8">Value3: Sub2</option>
   <option class="conditional value3" value="subValue9">Value3: Sub3</option>
</select>

JavaScript

$(function(){
    var conditionalSelect = $("#secondSelect"),
        // Save possible options
        options = conditionalSelect.children(".conditional").clone();
    
    $("#firstSelect").change(function(){
        var value = $(this).val();                  
        conditionalSelect.children(".conditional").remove();
        options.clone().filter("."+value).appendTo(conditionalSelect);
    }).trigger("change");
});