document.innerHTML('Hello world');

Hello, fellow js dev.

console.log("Hello");

document.innerHTML isn't a function. you can use document.body.innerHTML = 'Hello, World' instead

var rant = document.getElementById("rant");
var newPost = document.createElement("post");
var newTextNode = document.createTextNode("welcome!");
newPost.appendChild(newTextNode);
rant.appendChild(newPost);

Don't flame me for errors, hard enough to do on mobile. 😅

Web developers...

@Mitiko in my defense, he started in ecmascript.
If he had chosen another language I would've done it that language. 😋