If you chose to try this course with React hooks, it can start to get tricky here. My solution if you're struggling

Question

I did change a little, like putting in an empty array in anticipation of having to empty it anyway later. I also disliked the index method of locating which player to remove, so I used the players unique ids which feels safer to me.

App.js

import React, { useState } from "react";
import Header from "./Header";
import Player from "./Player";
import AddPlayerForm from "./AddPlayerForm";

function App() {
  const [players, setPlayers] = useState([]);
  const [playerId, setPlayerId] = useState(0);

  const handleScoreChange = (id, addend) => {
    setPlayers((players) => {
      const clone = [...players];
      clone.find((player) => player.id === id).score += addend;
      return clone;
    });
  };

  const handleRemovePlayer = (id) =>
    setPlayers((players) => players.filter((playerObj) => playerObj.id !== id));

  const createId = () => {
    setPlayerId((id) => id + 1);
    return playerId;
  };

  const handleAddPlayer = (name) =>
    setPlayers((players) => {
      const playerObj = {
        name,
        id: createId(),
        score: 0,
      };
      return [...players, playerObj];
    });

  return (
    <div className="scoreboard">
      <Header
        title="Scoreboard"
        totalPlayers={players.length}
        totalScore={[...players].reduce((acc, player) => acc + player.score, 0)}
      />

      {/* Players List */}
      {players.map((player) => (
        <Player
          {...player}
          key={player.id.toString()}
          removePlayer={handleRemovePlayer}
          changeScore={handleScoreChange}
        />
      ))}
      <AddPlayerForm addPlayer={handleAddPlayer} />
    </div>
  );
}

export default App;

AddPlayerForm.js

import React, { useState } from "react";

function AddPlayerForm(props) {
  const [nameField, setNameField] = useState("");
  const {addPlayer} = props;
  const handleNameFieldChange = (e) => setNameField(e.target.value);

  const handleSubmit = (e) => {
    e.preventDefault();
    addPlayer(nameField)
    setNameField("");
  };

  return (
    <form onSubmit={ handleSubmit }>
      <input
        type="text"
        value={nameField}
        onChange={handleNameFieldChange}
        placeholder="Enter a player's name"
      />

      <input type="submit" value="Add Player" />
    </form>
  );
}

export default AddPlayerForm;

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James Crosslin

James Crosslin

If you chose to try this course with React hooks, it can start to get tricky here. My solution if you're struggling