Two Errors I encounter whenever I run these codes.

Error 1:
TypeError: Cannot read property 'map' of undefined
DishDetail.render
C:/test/Coursera/React/confusion/src/components/DishdetailComponent.js:26
  23 |   </Card>  
  24 | </div>
  25 | <div className="col-12 col-md-5 m-1">
> 26 |   <h4>Comments</h4>         
     | ^  27 |   {
  28 |   this.props.comments.map(comment => (
  29 |     <ul className="list-unstyled">
  
  Error 2:
  TypeError: Cannot read property 'id' of undefined
DishDetail.render
C:/test/Coursera/React/confusion/src/components/DishdetailComponent.js:17
  14 | return(
  15 |   <div className="row">
  16 |     <div className="col-12 col-md-5 m-1">
> 17 |       <Card key={this.props.dish.id}>
     | ^  18 |         <CardImg top src={this.props.dish.image} alt={this.props.dish.name} />
  19 |         <CardBody>
  20 |         <CardTitle>{this.props.dish.name}</CardTitle>