React_井字棋

该项目是跟着react官网写的，由于是初学，就只用来记录自己的代码
如果和我一样是初学react建议看官网：react

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

// 按钮
function Square(props) {
    return (
        <button className="square"
                onClick={() => {
                    props.onClick()
                }}>
            {props.value}
        </button>
    );

}

// 棋盘格子
class Board extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            squares: Array(9).fill(null),
            xIsNext: true
        }
    }

    handleClick(i) {
        const squares = this.state.squares.slice()
        if (calculateWinner(squares)||squares[i]){
            return
        }
        squares[i] = this.state.xIsNext ? 'X' : 'O'
        this.setState({
            squares: squares,
            xIsNext: !this.state.xIsNext
        })
    }

    renderSquare(i) {
        return <Square value={this.state.squares[i]}
                       onClick={() => this.handleClick(i)}/>;
    }

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

        return (
            <div>
                <div className="status">{status}</div>
                <div className="board-row">
                    {this.renderSquare(0)}
                    {this.renderSquare(1)}
                    {this.renderSquare(2)}
                </div>
                <div className="board-row">
                    {this.renderSquare(3)}
                    {this.renderSquare(4)}
                    {this.renderSquare(5)}
                </div>
                <div className="board-row">
                    {this.renderSquare(6)}
                    {this.renderSquare(7)}
                    {this.renderSquare(8)}
                </div>
            </div>
        );
    }
}

class Game extends React.Component {
    render() {
        return (
            <div className="game">
                <div className="game-board">
                    <Board/>
                </div>
                <div className="game-info">
                    <div>{/* status */}</div>
                    <ol>{/* TODO */}</ol>
                </div>
            </div>
        );
    }
}

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


const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Game/>);

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.length; i++) {
        const [a, b, c] = lines[i]
        if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
            return squares[a]
        }
    }
    return null
}