JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" onkeyup="return ChangeCharCase(event,this);" onchange="alert('on change event triggered.');"/>
<br/>
<br/>
<input type="text" onchange="alert('on change event triggered.');"/>

JavaScript

function ChangeCharCase(evt,obj)
{
    //if(obj.value != obj.value.toUpperCase()) 
	obj.value = obj.value.toUpperCase();
    return true;
}