Both Presentational and Container Components can only contain other Presentational Components

Container Components can only contain Presentational Components while Presentational Components can only contain Container Components

Both Presentational and Container Components can contain other Presentational and Container Components

Container Components can contain any other components while Presentational Components cannot contain any other components

There are many actions on the state and they could use some structure.

Many children components need access to actions on the app state.

Same state is needed in many children components.

React's state is limited.

By using component props

By using an HOC that receives the list of state elements needed

By using function components

By using pure components

Perf.report()

Perf.printWasted()

Perf.printOperations()

Using the react_perf flag

Using the react_record flag

Using the react_debug flag

In production, you get a generic error message with a URL to the problem.

In production, all errors are catched and emitted with an 'error' event.

The component will attempt to call the onError method.

const func = (funcArg = () => {}) => {};

const func = (funcArg = ()) => {};

const func = (funcArg = =>) => {};

const func = funcArg = () => { => {} }

expect(tree).toMatchSnapshot();

expect(tree).toMatch(snapshot);

expect(tree.snapshot).toMatch;

Ensure that React updates don't rerender child components

Render a way that allows graphics processors to render it faster

Get access to the output of a component for testing purposes

Let React render the minimum of what's required for the user

toMemory

shallow

toTestOutput

memoryOnly

ReactTestUtils.onClick

ReactTestUtils.Simulate

ReactTestUtils.User

ReactTestUtils.fireEvent

By using global variables

By using the context API

By using Pure Components

A component that will not render on updated props/state if the new matches the old.

A component that cannot have private state.

A component that will purely represent a UI.

Import A from 'component/A'

Import A from 'A';

Import A from './lib/components/A';

<div className={"lead", this.props.hidden && "hidden"}>

<div className={["lead", this.props.hidden && "hidden"]}>

let classNames = "lead"; if (this.props.hidden) classNames += " hidden"; Then Use: <div className={classNames}>

let classNames = ["lead"]; if (this.props.hidden) classNames.push("hidden"); Then Use: <div className={classNames}>