import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
function Square (props) {
return (
<button
className="square"
onClick={props.onClick}
>
{props.value}
</button>
);
}
class Board extends React.Component {
renderSquare(i) {
return (
<Square
value={this.props.squares[i]}
onClick={() => this.props.onClick(i)}
/>
);
}
render() {
return (
<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 {
constructor(props){
super(props);
this.state = {
history : [{
squares : Array(9).fill(null),
}],
stepNumber : 0,
xIsNext: true,
};
}
jumpTo(step){
this.setState({
stepNumber : step,
xIsNext : (step % 2) === 0,
});
}
handleClick(i){
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.xIsNext?'X':'O';
this.setState({
history : history.concat([{
squares : squares,
}]),
stepNumber : history.length,
xIsNext : !this.state.xIsNext,
});
}
render() {
const history = this.state.history;
const current = history[this.state.stepNumber];
const winner = calculateWinner(current.squares);
const moves = history.map((step,move) => {
const desc = move?
'Go to move #' + move :
'Go to game start';
return (
<li key={move}>
<button onClick={() => this.jumpTo(move)}>{desc}</button>
</li>
);
});
let status;
if(winner){
status = 'Winner: ' + winner;
}else{
status = 'Next player: ' + (this.state.xIsNext ? 'X' : 'O');
}
return (
<div className="game">
<div className="game-board">
<Board
squares={current.squares}
onClick={(i) => this.handleClick(i)}
/>
</div>
<div className="game-info">
<div>{status}</div>
<ol>{moves}</ol>
</div>
</div>
);
}
}
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;
}
// ========================================
ReactDOM.render(
<Game />,
document.getElementById('root')
);