Elyses Destructured Enchantments
10 Points
array-destructuring
object-destructuring
Instructions
Elyse, magician-to-be, continues her training. She has a deck of cards she wants to manipulate.
To make things easier, she usually only starts with cards numbered 2 to 10, although some of the tricks may involve additional (face) cards.
<!-- prettier-ignore-start -->Note
There are many ways to shuffle the cards around, but to keep up the illusion of magic, it is vital that no single method is used, e.g. Elyse doesn't use splice, slice, shift, unshift, push, at.
The array accessor array[index] and object accessor (object[key] and object.key) are also never to be used.
Want to help Elyse level up her magic?
<!-- prettier-ignore-start -->Advanced Concept
Every function can be implemented using the parameters and a function body with a single return expression.
1. Get the first card
Elyse will summon the first card in the deck without using the array[index], .at(index), or .shift().
It's just like magic.
const deck = [5, 9, 7, 1, 8];
getFirstCard(deck);
// => 52. Get the second card
Elyse performs sleight of hand and summons the second card in the deck without using the array[index] or .shift().
const deck = [3, 2, 10, 6, 7];
getSecondCard(deck);
// => 23. Swap two cards
Elyse will make the two cards of the deck switch places. She doesn't need to call a single function.
const deck = [10, 7];
swapTwoCards(deck);
// => [7, 10]4. Shift three cards around
In order to perform some more sleight of hand, Elyse takes three cards and quickly moves the top card to the back, making the middle card the first card and the old bottom card the middle card. She doesn't need to call a single function.
const deck = [2, 6, 10];
shiftThreeCardsAround(deck);
// => [6, 10, 2]5. Pick the named pile
Elyse will separate the deck into two piles.
She then asks the observer to pick one of the two piles, which we'll name chosen.
The disregarded pile is no longer relevant, which she makes disappear.
She doesn't need to call a single function.
const deck = [5, 4, 7, 10];
const chosen = [5, 4];
const disregarded = [7, 10];
pickNamedPile({ chosen, disregarded });
// => [5, 4]5. Swap the picked pile
Unfortunately the observer keeps picking the "wrong" pile, but with some clever fast magic, Elyse renames the chosen pile to be disregarded and the disregarded pile to be the chosen pile.
She doesn't need to call a single function.
const deck = [5, 4, 7, 10];
const chosen = [5, 4];
const disregarded = [7, 10];
swapNamedPile({ chosen, disregarded });
// => { chosen: [7, 10], disregarded: [5, 4] }Elyses Destructured Enchantments
10 Points
array-destructuring
object-destructuring
Instructions
Elyse, magician-to-be, continues her training. She has a deck of cards she wants to manipulate.
To make things easier, she usually only starts with cards numbered 2 to 10, although some of the tricks may involve additional (face) cards.
<!-- prettier-ignore-start -->Note
There are many ways to shuffle the cards around, but to keep up the illusion of magic, it is vital that no single method is used, e.g. Elyse doesn't use splice, slice, shift, unshift, push, at.
The array accessor array[index] and object accessor (object[key] and object.key) are also never to be used.
Want to help Elyse level up her magic?
<!-- prettier-ignore-start -->Advanced Concept
Every function can be implemented using the parameters and a function body with a single return expression.
1. Get the first card
Elyse will summon the first card in the deck without using the array[index], .at(index), or .shift().
It's just like magic.
const deck = [5, 9, 7, 1, 8];
getFirstCard(deck);
// => 52. Get the second card
Elyse performs sleight of hand and summons the second card in the deck without using the array[index] or .shift().
const deck = [3, 2, 10, 6, 7];
getSecondCard(deck);
// => 23. Swap two cards
Elyse will make the two cards of the deck switch places. She doesn't need to call a single function.
const deck = [10, 7];
swapTwoCards(deck);
// => [7, 10]4. Shift three cards around
In order to perform some more sleight of hand, Elyse takes three cards and quickly moves the top card to the back, making the middle card the first card and the old bottom card the middle card. She doesn't need to call a single function.
const deck = [2, 6, 10];
shiftThreeCardsAround(deck);
// => [6, 10, 2]5. Pick the named pile
Elyse will separate the deck into two piles.
She then asks the observer to pick one of the two piles, which we'll name chosen.
The disregarded pile is no longer relevant, which she makes disappear.
She doesn't need to call a single function.
const deck = [5, 4, 7, 10];
const chosen = [5, 4];
const disregarded = [7, 10];
pickNamedPile({ chosen, disregarded });
// => [5, 4]5. Swap the picked pile
Unfortunately the observer keeps picking the "wrong" pile, but with some clever fast magic, Elyse renames the chosen pile to be disregarded and the disregarded pile to be the chosen pile.
She doesn't need to call a single function.
const deck = [5, 4, 7, 10];
const chosen = [5, 4];
const disregarded = [7, 10];
swapNamedPile({ chosen, disregarded });
// => { chosen: [7, 10], disregarded: [5, 4] }