JSFiddle - React, Tailwind, and code Playground

HTML

Vorname: <input id="vorname"/><br>  
	Nachname: <input id="nachname"/><br>  
	Kompletter Name: <span id="ganz"></span> 
	  
	<script>  
	function updateGanz(){  
	    var ganz = document.getElementById("vorname").innerText + " " + document.getElementById("nachname").innerText;  
    document.getElementById("ganz").innerHTML = ganz;  
}  
	$("#vorname, #nachname").bind("change keyup", function(){  
	    updateGanz();  
	});  
	updateGanz();  
	  
</script>