JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<body>

<p>Enter text and Click the button to display the vowel count</p>
<input type="text" id="text" />
<button onclick="myFunction(document.getElementById('text').value)">Try it</button>

<p id="demo"></p>

<script>
function myFunction(text) {
document.getElementById("demo").innerHTML='';
    var str = text.toLowerCase();
    var arr=['a','i','o','e','u'];
    
    for(i=0;i<arr.length;i++)
    {
    	document.getElementById("demo").innerHTML+= arr[i]+" Found "
        + ((str.split(arr[i]).length)-1)+"<br/>";	
        
    }
    
    
}
</script>

</body>
</html>