JSFiddle - React, Tailwind, and code Playground

HTML

<input type="file" id="photo1" name="photo1"/>
<input id="clickme" type="button" value="Get file name"/>

JavaScript

var btn = document.getElementById("clickme");

btn.onclick = function() {
   var pic = document.getElementById("photo1").value.split(/(\\|\/)/g).pop();   
   var filename = pic.substring(0, pic.lastIndexOf("."));
   alert(filename); 
};