react第一个小项目

根据https://react.docschina.org/tutorial/tutorial.html学习

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';

// class Square extends React.Component {
//     render() {
//         function Square(props) {
//             return (
//
//                     {props.value}
//
//             );
//         }
//         return (
//              this.props.onClick()}>
//                 {this.props.value}
//
//         );
//     }
// }

function Square(props) {
    return (

            {props.value}

    );
}

function calculateWinner(squares) {
    const lines = [
        [0, 1, 2],
        [3, 4, 5],
        [6, 7, 8],
        [0, 3, 6],
        [1, 4, 7],
        [2, 5, 8],
        [0, 4, 8],
        [2, 4, 6],
    ];
    for (let i = 0; i < lines xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed>
        );
    }

    render() {
        // const winner = calculateWinner(this.state.squares);
        // let status;
        // if(winner){
        //     status = 'Winner:'+winner;
        // }else{
        //     status = 'Next player: ' + (this.state.xInNext ? 'X' : 'O');
        // }

        return (

                {/* {status} */}

                    {this.renderSquare(0)}
                    {this.renderSquare(1)}
                    {this.renderSquare(2)}

                    {this.renderSquare(3)}
                    {this.renderSquare(4)}
                    {this.renderSquare(5)}

                    {this.renderSquare(6)}
                    {this.renderSquare(7)}
                    {this.renderSquare(8)}

        );
    }
}

class Game extends React.Component {
    constructor() {
        super();
        this.state = {
            history: [{
                squares: Array(9).fill(null),
            }],
            stepNumber: 0,
            xInNext: true,
        }
    }

    handleClick(i) {
        // const history = this.state.history;
        const history = this.state.history.slice(0, this.state.stepNumber + 1);
        const current = history[history.length - 1];
        const squares = current.squares.slice();
        if (calculateWinner(squares) || squares[i]) {
            return;
        }
        squares[i] = this.state.xInNext ? 'X' : 'O';
        this.setState({
            history: history.concat([{
                squares: squares,
            }]),
            // squares: squares,
            stepNumber: history.length,
            xInNext: !this.state.xInNext,
        });
    }

    jumpTo(step) {
        this.setState({
            stepNumber: step,
            xInNext: (step % 2) ? false : true,
        })
    }

    render() {
        const history = this.state.history;
        // const current = history[history.length - 1];
        const current = history[this.state.stepNumber];
        const winner = calculateWinner(current.squares);

        const moves = history.map((step, move) => {
            const desc = move ? 'Move #' + move : 'Game start';
            return (

                     this.jumpTo(move)}>{desc}

            );
        });

        let status;
        if (winner) {
            status = 'Winner:' + winner;
        } else {
            status = 'Next player: ' + (this.state.xInNext ? 'X' : 'O');
        }

        return (

                     this.handleClick(i)}
                    />

                    {status}
                    {moves}

        );
    }
}

function UserGreeting(props) {
    return Welcome back!;
}

function GuestGreeting(props) {
    return Please sign up.;
}

function Greeting(props) {
    const isLoggedIn = props.isLoggedIn;
    if (isLoggedIn) {
        return ;
    }
    return ;
}

ReactDOM.render(
    // ,
    ,
    document.getElementById('root')
);

// ========================================

// ReactDOM.render(
//     ,
//     document.getElementById('root')
// );