Hello.
I’m following a tutorial on YouTube to get started with ReactJS. I’ve downloaded the starter template from reactjs.org I just want to see my first "Hello World! on the screen. But I fail.
I have an index.html file.
And I have the app.js file.
Please, check screenshots below.
Why it doesn’t work? I reviewed several times my tutorial. I don’t understand what is wrong with my code.
Could you please help. Can’t wait to get start and to move further 
Thank you very much in advance.
Helena
Hi @Helena_G! Welcome to the forums 
When you preview your page in your browser, do you see any errors in the Console in your browser developer tools?
Really strange! Can you copy/paste your code here? You can use this button to format your code correctly as part of the response:
From the screenshots, what you have should work.
class App extends React.Component() {
should be
class App extends React.Component {
There should be no parens in the extends clause (you can but just not in this case).
Just curious, what drives your intuition about parentheses in cases like this?
The extends clause accepts any expression. So you can put just about anything there, including a function (invoked with parens) that you can call and return a class with.
class Animal {}
class FeralAnimal {}
function getAnimal () {
return Math.random() < 0.5 ? Animal : FeralAnimal;
}
class Cat extends getAnimal() {}
let missPrincess = new Cat();
console.log(missPrincess instanceof FeralAnimal); // ???
This is used with class-based mixins.
Ah right, this is JavaScript:
class A extends class B extends function(){ return function(){
return "senocular".constructor
}() }() { } { }
