PabloRegen

// Sync callback
function greetings(callback) {
  callback();
}
greetings(() => { console.log('Hi'); });
moreWork(); // will run after console.log

// Async callback
const fs = require('fs');
fs.readFile('/file.md', function callback(err, data) { // fs.readFile is an async method provided by Node

PabloRegen

// Blocking
const fs = require('fs');
const data = fs.readFileSync('/file.md'); // blocks here until file is read
console.log(data);
moreWork(); // will run after console.log

// Non-blocking
const fs = require('fs');
fs.readFile('/file.md', (err, data) => {
  if (err) throw err;

PabloRegen

// Synchronous: 1,2,3
alert(1);
alert(2);
alert(3);

// Asynchronous: 1,3,2
alert(1);
setTimeout(() => alert(2), 0);
alert(3);

PabloRegen

class App extends Component {
    // All previous methods ...

    render() {
        const { boardStatus, isGameRunning, generation, speed } = this.state;

        return (
            <div>
                <h1>Game of Life</h1>
                <BoardGrid boardStatus={boardStatus} onToggleCellStatus={this.handleToggleCellStatus} />

PabloRegen

class App extends Component {
    state = {...};
    runStopButton = () => {...}
    handleClearBoard = () => {...}
    handleNewBoard = () => {...}
    handleToggleCellStatus = () => {...}
    handleStep = () => {...}
                        
    handleSpeedChange = newSpeed => {
        this.setState({ speed: newSpeed });

PabloRegen

class App extends Component {
    state = {...};
    runStopButton = () => {...}
    handleClearBoard = () => {...}
    handleNewBoard = () => {...}
    handleToggleCellStatus = () => {...}

    handleStep = () => {
        const nextStep = prevState => {
            const boardStatus = prevState.boardStatus;

PabloRegen

class App extends Component {
    state = {...};
    runStopButton = () => {...}
    handleClearBoard = () => {...}
    handleNewBoard = () => {...}

    handleToggleCellStatus = (r,c) => {
        const toggleBoardStatus = prevState => {
            const clonedBoardStatus = JSON.parse(JSON.stringify(prevState.boardStatus));
            clonedBoardStatus[r][c] = !clonedBoardStatus[r][c];

PabloRegen

class App extends Component {
    state = {...};
    runStopButton = () => {...}
    
    handleClearBoard = () => {
        this.setState({
            boardStatus: newBoardStatus(() => false),
            generation: 0
        });
    }

PabloRegen

class App extends Component {
    state = {...};

    runStopButton = () => {
        return this.state.isGameRunning ?
        <button type='button' onClick={this.handleStop}>Stop</button> :
        <button type='button' onClick={this.handleRun}>Start</button>;
    }
    
    // Other methods ...

PabloRegen

class App extends Component {
    state = {
        boardStatus: newBoardStatus(),
        generation: 0,
        isGameRunning: false,
        speed: 500
    };

    // Other methods ...