How to guess the paragraph first word using javascript?

Html page:

<button onclick="myFunction()">Try it</button>

<p id="P4"></p>

Javascript page:

<script>

    function myFunction() {

        var str = "Hello world, welcome to the universe.";

        var n = str.startsWith("Hello");

        document.getElementById("demo").innerHTML = n;

    }

</script>

Output:

true