make javascript variable update live with text input

hey this is an edited version of my first post:

Pretty much what I want to do is have a text input box that stores its contents in a javascript variable. The catch is I want it to happen live, so the variable will update automatically say, ever .2 seconds without the user needing to press a submit button. Thanks

Solution

Are you looking for the two way data binding? Something like this: https://codepen.io/manishiitg/embed/ZYOmbB?

<html>
    <head>
        <script src="https://code.angularjs.org/1.3.8/angular.min.js"></script>
        <script>
            var mainMod = angular.module('MainApp', []);
            mainMod.controller('MainCtrl', function ($scope) {
                $scope.text = '';
            });
        </script>
    </head>
    <body ng-app='MainApp'>
        <div ng-controller='MainCtrl'>
          <div>
            Change Text Here: 
            <input type='text' ng-model='text' />
          </div>
          <div>
            <p>Text: {{text}}</p>
          </div>
        </div>
    </body>
<html>

You can achieve that with Angular, React and Vue.js framework, even with jQuery. Perhaps you should try one of the frameworks that solves your needs quickly.

If you choose Angular, I recommend you to make the tutorial steps, specially this part: https://angular.io/tutorial/toh-pt1#two-way-binding