Cannot read property '0' of undefined - stuck with reactjs tutorial

Question

I stuck at the "Storing a history" part of the tutorial, trying to pull state up from Board to Game. I've removed constructor from Board and was trying to change Board so that it takes squares via props:

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

but it fails..

code: https://codepen.io/gka/pen/eBgapz

Asaf Aviv · Accepted Answer · 2018-10-29 00:48:14Z

5

In your example, you pass in squares as props. So you need to change

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

into

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

Because this.props already refers to the squares you passed in.

edited Oct 29, 2018 at 0:48

Asaf Aviv

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answered Nov 20, 2016 at 17:10

zabeltech

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Comments

mgPePe · Accepted Answer · 2018-10-28 22:09:27Z

0

I had my App render Board instead of Game, so that was the reason it wasn't working.

answered Oct 28, 2018 at 22:09

mgPePe

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