ib.js

This JS library implements the data structures outlined in the IB Computer Science Pseudocode Guide exactly as they are. Use it to experiment with the data structures or what ever you would like to do when studying CS!

Installation

The package is available as @sampoder/ib.js on NPM which after installation can be used like:

const { Stack, Collection, Queue } = require('@sampoder/ib.js')

You can also import it directly from Skypack through URL imports:

import { Stack, Collection, Queue } from 'https://cdn.skypack.dev/@sampoder/ib.js';

Make sure your script has the property type="module" set.

Collections

The Collection() class has the following methods:

| Method | Description | | ----------- | ----------- | | addItem(x) | Add item to collection | | getNext() | Get the next item in the collection | | resetNext() | Go back to the start of the collection | | hasNext() | Test if the next item exists | | isEmpty() | Test if a collection is empty |

Stacks

The Stack() class has the following methods:

| Method | Description | | ----------- | ----------- | | push() | Push an item onto the top of the stack | | pop() | Removes and returns the item on the top of the stack | | isEmpty() | Test if a stack is empty |

Queues

The Queue() class has the following methods:

| Method | Description | | ----------- | ----------- | | enqueue() | Adds an item to the back of the queue | | dequeue() | Returns and removes the first item in the queue | | isEmpty() | Test if a queue is empty |

Note: these are all minor adaptations of preexisting JS functionality but I found it helpful to have it presented in this way to understand what the course meant.

Sample Code

Here is some messy sample code to help you get an idea of how the library works.

const { Stack, Collection, Queue } = require('@sampoder/ib.js')

let s = new Stack()

console.log(s.push("hi"))

console.log(s.push("sam"))

console.log(s.pop())

console.log(s.isEmpty())

let q = new Queue()

q.enqueue(2)

q.enqueue(1)

console.log(q.dequeue())

let c = new Collection()

c.addItem("sam")

c.addItem("p")

c.addItem("2")

c.addItem("3")

c.addItem("4")

while(c.hasNext()){
  console.log(c.getNext())
}

c.resetNext()

console.log(c.getNext())