Tic-Tac-Toe-1a.jsx

// Game component:

handleClick(i) {
    const locations = [
      [1, 1],
      [2, 1],
      [3, 1],
      [1, 2],
      [2, 2],
      [3, 2],
      [1, 3],
      [2, 3],
      [3, 3]
    ];
    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,
          location: locations[i]
        }
      ]),
      stepNumber: history.length,
      xIsNext: !this.state.xIsNext
    });
  }