JSFiddle - React, Tailwind, and code Playground

HTML

<br />&nbsp;
Get alert with inserting a + sign: <input type="text" id="testField" class="data" />

CSS

body { font-family:Tahoma; font-size:9pt }

JavaScript

$(document).ready(function(){
    $(".data").bind('keydown',function(e){
        if(e.which == 107){
            alert('Plus sign entered');
        });
    });
});