How to insertBefore() element in body tag?

Question

I am trying to use insertBefore in js like this:

var p = document.createElement("p");
p.innerHTML = "test1";
document.body.insertBefore(p, null);

var p = document.createElement("p");
p.innerHTML = "test2";
document.body.insertBefore(p, null);

But that would add the last p element just before the close of the body tag, how could I use it so it will be added to the top when it opens? So the last element added will be the first element inside the body tag.

I tried:

document.body.insertBefore(p, document.getElementsByTagName('body')[0]);

But firebug shows:

Node was not found" code: "8

Answer 1

You can get the first child of the body element with the firstChild property. Then use it as the reference.

const p = document.createElement("p");
p.textContent = "test1";
document.body.insertBefore(p, document.body.firstChild);

I modernized your code for reasons :)