Basic JavaScript/TypeScript practice problems by common topics

This repository was initially created for me to review and/or practice basic JavaScript/TypeScript concepts and built-in functionalities such as map, filter, reduce, etc. However, along the way I realized this could be a valuable resource for others as well. Therefore, I decided to organize it in a way that others can use it as well if they desire. It contains sample exercises and my solutions and tests written for those problems.

Who is it for?

These exercises are suitable for someone new to JavaScript/TypeScript and/or unit testing and wants to improve or review their skills.

Purpose

The main purpose of this repository is to practice basic JavaScript and/or TypeScript topics in a TDD (Test Driven Development) approach. It contains sample problems in 10 different categories.

The problems are generated with the help of ChatGPT, however, their solutions and the tests are entirely written by me.

Topic Categories

1. Arrays:
   • Remove Duplicate, Merge Sorted, Rotate Array, Subarray Sum, Permutation, etc.
2. Strings:
   • Palindrome Check, Anagram Check, Reverse String, Wildcard Matching, Regex Parser, etc.
3. Functions:
   • Basic Closure, Function Composition, Currying, Memoization, Partial Application, Debounce, Throttle, Recursive Function, Function Pipeline and Async/Await.
4. Objects:
   • Shallow Clone, Merge Objects, Object Keys and Values, Deep Clone, Object Invert, Filter Object, Object Map, Merge Deep Objects, Object Difference, Flatten Object.
5. Promises:
   • Basic Promise Creation, Promise Chaining, Promise Rejection, Promise All, Promise Race, Promise Timeout, Promise Retry, Promise Progress, Promise Parallel Limit and Promise Waterfall.
6. Asynchronous Programming:
   • Simple Timeout, Fetch Data, Sequential Execution, Parallel Execution, Promise All Settled, Asynchronous Map, Throttle, Debounce, Caching with Async Function and Race Condition Prevention.
7. Classes:
   • Class Creation, Inheritance, Static Method, Getter and Setter, Class Extension, Class Composition, Class Decorator, Event Handling with Classes, Observable Pattern and Mixin Composition.
8. Event Handling:
   • Basic Event Listener, Custom Event Listener, Event Propagation, Event Delegation, Multiple Event Listeners, Event Bubbling, Event Emitter Class, Drag and Drop Implementation, Event Bus Implementation and Cross-Browser Compatibility.
9. Modules:
   • Basic Module Export, Default Export, Named Exports, Module with Dependencies, Module with Configuration, Module with Classes, Module with Asynchronous Operations, Module with Error Handling, Module with Caching and Module with Dynamic Import.
10. DOM Manipulation:
    • Text Content Manipulation, Element Style Manipulation, Element Creation and Insertion, Event Handling with DOM Elements, Element Attribute Manipulation, Element Removal, Dynamic Element Creation and Event Handling, Element Style Animation, Form Input Handling and Complex DOM Manipulation.

Directory Structure

• problems/: This folder contains the markdown files for each category of exercises. Each markdown file should include the exercises and some example test cases for that specific category.
• exercises/: The exercises folder contains the starter .ts files for the exercises.
• src/: This folder should contain the folders solutions/ and tests/.
  • solutions/: The solutions/ folder should contain the TypeScript implemention of the exercises. The file names match the corresponding .ts exercise and markdown files in the exercises/ and problems/ folder respectively. For this repository, this folder already contains my solutions written by me.
  • tests/: This folder contains test files for each category of exercises. Each test file should correspond to the solved exercises in the solutions/ folder.
• jest.config.js: Configuration file for Jest.
• tsconfig.json: Configuration file for TypeScript.
• eslint.config.mjs: Configuration file for ESLint.

Setup

Prerequisites

• Node.js (version 12 or higher)
• npm or yarn

Installation

1. Fork the repository:

   If you would like to use this repository to write your own solutions, then please Fork this repo. Otherwise,

   Go to the repository page and click the "Fork" button in the top-right corner of the page.

2. Clone the repository:

   HTTPS

   git clone https://github.com/SamihaNanjiba/typescript-exercises-and-tests.git

   SSH

   [email protected]:SamihaNanjiba/typescript-exercises-and-tests.git

   Change directory to the project folder:

   cd typescript-exercises-and-tests

3. Install dependencies:

   Using npm:

   npm install

How to Use

Solutions

I have already created starter files in the exercises/ folder. You can start writing your implementations in them. In that case, change the refence of the test files to that folder. For example, instead of import { findMax, removeDuplicates, reverseArray } from "../solutions/1_arrays.ts";, change it to import { findMax, removeDuplicates, reverseArray } from "../exercises/1_arrays.ts";.

Another option will be to entirely remove my solutions from the solutions folder and copy the starter files there and start implementing. In that case, no need to change the import statements in the test files.

Tests

This repository is setup with Jest, but feel free to remove it and use your own prefered framework, e.g. Mocha for writing unit tests.

Contributing

If you'd like to contribute to this repository, via fixing any errors, bugs, updating the exercise problems and their sample test cases, please fork the project, create a new branch for your update or bug fix, and submit a pull request. Contributions are welcome!