elyses-enchantments

Elyses Enchantments

Welcome to Elyses Enchantments on Exercism's JavaScript Track. If you need help running the tests or submitting your code, check out HELP.md. If you get stuck on the exercise, check out HINTS.md, but try and solve it without using those first :)

Introduction

In Javascript, an array is a list-like structure with no fixed length which can hold any type of primitives or objects, even mixed types. The array elements can be accessed by their index.

Example of an array declaration and accessing an element by index:

const numbers = [1, 'two', 3, 'four'];
numbers[2];
// => 3

Instructions

As a magician-to-be, Elyse needs to practice some basics. She has a stack of cards that she wants to manipulate.

To make things a bit easier she only uses the cards 1 to 10.

1. Retrieve a card from a stack

In order to pick a card, return the card at position position from the given stack.

const position = 2;
getItem([1, 2, 4, 1], position);
// => 4

2. Exchange a card in the stack

Perform some sleight of hand and exchange the card at position position with the new card provided. Return the adjusted stack.

const position = 2;
const newCard = 6;
setItem([1, 2, 4, 1], position, newCard);
// => [1, 2, 6, 1]

3. Insert a card at the top of the stack

Make a card appear, by inserting a new card at the top of the stack. Return the adjusted stack.

const newCard = 8;
insertItemAtTop([5, 9, 7, 1], newCard);
// => [5, 9, 7, 1, 8]

4. Insert a card at the bottom of the stack

Make a card appear, by inserting a new card at the bottom of the stack. Return the adjusted stack.

const newCard = 8;
insertItemAtBottom([5, 9, 7, 1], newCard);
// => [8, 5, 9, 7, 1]

5. Remove a card from the stack

Make a card disappear by removing the card the given position from the stack. Return the adjusted stack.

const position = 2;
removeItem([3, 2, 6, 4, 8], position);
// => [3, 2, 4, 8]

6. Remove the top card from the stack

Make a card disappear by removing the card at the top of the stack. Return the adjusted stack.

removeItemFromTop([3, 2, 6, 4, 8]);
// => [3, 2, 6, 4]

7. Remove a card from the bottom of the stack

Make a card disappear by removing the card at the bottom of the stack. Return the adjusted stack.

removeItemAtBottom([8, 5, 9, 7, 1]);
// => [5, 9, 7, 1]

8. Check the size of the stack

Check whether the size of the stack is equal a given stackSize or not.

const stackSize = 4;
checkSizeOfStack([3, 2, 6, 4, 8], stackSize);
// => false

Source

Created by

• @ovidiu141
• @SleeplessByte

Contributed to by

• @peterchu999