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Project: leaderboard

JavaScript · Unit 10: More on functions

Your leaderboard sorts the players from most to fewest points. Remember that sort changes the array: sort a copy made with [...].

And something new: map passes your arrow a second piece of data, each element's position, counting from 0.

const players = [
  { name: "Leo", pts: 12 },
  { name: "Ann", pts: 15 },
];
const board = [...players].sort(
  (a, b) => b.pts - a.pts
);
const lines = board.map(
  (p, i) => `${i + 1}. ${p.name}`
);
console.log(lines);
console.log(players[0].name);

Prints

[ '1. Ann', '2. Leo' ]
Leo

Exercises in this lesson

You do them in the app, which checks them on the spot and explains why.

  1. 1. Complete the code

    Fill in compare: whoever has more points goes first and, if they're tied, alphabetical order. It should print Ann, Leo and Mia.

  2. 2. Write the code

    Write rank(players), which returns the players in leaderboard order: whoever has more points first and, if they're tied, in alphabetical order. Sort a copy, so you don't mess up the original list.

  3. 3. Write the code

    You already have rank. Write standings(players), which returns an array of strings like "1. Ann (15)", one per player, in leaderboard order.

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