Thank you for the reply! It clarifies a lot. Nonetheless, if I'm not mistaken, we are using it inside the constructor: this .state = { todos: this .props.dataInterface.getAllTodos(), By not passing the props, I get "dataInterface undefined". I was only able to spot it by comparing the code with your repo, which has the super(props) mentioned above. Maybe we are using different React (or other dependencies) releases? Once again, thanks for the tutorial

Thanks a lot for the tutorial, it's been very helpful. Quick note, I think you've missed the props on the TodoApp.js snippet: constructor (props) { super (props);