React Best Practices

1. We always create one component per file. No matter how small it is.
2. Normaly we call React Components a functional component. because it literally a function. there is another type of component in React is Class Component. It use to some type of record keeping.

var SearchBar = () => {
    return <input />
}

3. Class Based components must have render method declaration. Otherwise you will get an error.
4. You should always start with functional Components and while refactoring you can introduce class based component to make them more intelligent.
5. State is a plain javascript object that is use to record in react to use events. Each class based component that we define as it's onw state object. what ever a component state change, component immidiatly rerendered and it also forces all of it's childers to be rerendered as well.
6. Functional components do not have state only class based components do.
7. State is a plain javascript object that is used to record in React an user events.
8. You must update state by using this.setState() throughout the component except in constructor of the class based component.
9. Controlled field is a form element (like input) whose value is set by the state property. and it's value changes only when the state changes.
10. To instantiat an object of js class in JSX just put name of the class with angle brackets. Where App is the class.
11. Event handler is the function in the class that should be ran whenever the event occurs.
12. We pass the event handlers to the element we want to monitor for events.
13. Each class based component that we define has it's own state object. Whenever component state changed, component immidiatly rerendered. and also forces all of it's childerns to rerender as well.
14. On top of Redux, we have Webpack, Redux Router, React Router, Redux Promise, Redux thunk.
15. Redux contains the state of the whole application.
16. Redux is more about to control the data.
17. In Redux, Reducer is just a function which returns the application state. Since one application can have many different pieces of states hence we can have many different reducers.
18. An application state generates by the Reducer function.
19. Redux servers to constuct an application state and react provides the view to display that state.
20. Action creator is a function that return an action.
21. Action creator returns an object called action. and returned action automatically sent to all reducers.
22. In redux State is an application state. Whereas in React state is the component state and both states are not connected in any way. Even redux should call their state variable something else.