JSFiddle - React, Tailwind, and code Playground

HTML

<select id="myDropdown">
    <option value="number">Number</option>
    <option value="text">Text</option>
    <option value="float">Float</option>
</select>
<input type="text" id="myInput"  value="" />

JavaScript

$("#myInput").on("keydown", function(e) {
    var dropdown = $("#myDropdown").val();
    var inputValue = $(this).val();
    
    if(dropdown === "number") {
        //"Do your number validation here
    } else if(dropdown === "text") {
        //Do your text validation here
    } else  if(dropdown === "float") {
        //Do your float validation here
    }
});