Why is code after [removed]() not executed?

Question

I have the follwing JavaScript.

Answer 1

document.write can only be used during the initial loading of the document.

If you want to insert your H1 when the function is called, you may replace

document.write("
 Just a javascript demo
");

with

var h1 = document.createElement('h1');
h1.innerHTML = " Just a javascript demo";
document.body.appendChild(h1);