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rashell smith
15,405 PointsMy Delta Is undefined
handleScoreChange = (index, delta) => { this.setState( prevState => ({ score: prevState.players[index].score += delta })); console.log('index:'+ index, 'delta:' + delta); } handleRemovePlayer = (id) => { this.setState( prevState => { return { players: prevState.players.filter(p => p.id !== id) }; }); }
render() { return ( <div className="scoreboard"> <Header title="Scoreboard" totalPlayers={this.state.players.length} />
{/* Players list */}
{this.state.players.map( (player, index)=>
<Player
name={player.name}
score={player.score}
id={player.id}
key={player.id.toString()}
index={index}
changeScore={this.handleScoreChange}
removePlayer={this.handleRemovePlayer}
/>
)}
</div>
);
} }
This is just some of my code I keep getting the error that Delta is undefined when I add a the index to the function parameters.
1 Answer
Uche Onuekwusi
18,070 Pointscheck both your player and counter components. The index props must passed in at the counter component mentioned in the player component module. Then you store let index = props.index in the counter component and include it in in your onclick function call in the counter module. like this : onClick = {()=>props.changeScore(index,-1)}