Observable State

MobX adds observable capabilities to existing data structures like objects, arrays and class instances. This can simply be done by annotating your class properties with the @observable decorator.

class Todo {
    id = Math.random();
    @observable title = "";
    @observable finished = false;
}

Using observable is like turning a property of an object into a spreadsheet cell. But unlike spreadsheets, these values can be not only primitive values, but also references, objects and arrays. You can even define your own observable data sources.