Home/Projects/ Project - Calculator App/
Home/Projects/Project - Calculator App/

Calculator App

Create your own Calculator in JavaScript available on the web with a beautiful design. Additionally, Add an ability to switch between dark and light modes.
Designed by
Milena Ulman
It's free and always will. You can use this design for your portfolio/website without any limitations. Additionally, you can share the completed project wherever you want.

Read me first

The goal of this project is to build a Calculator App similar to the design above.
Technologies & tools will be proposed down below but feel free to use different ones if you're more familiar with them. Have fun along the way.
Project requirements
  • The application looks similar to the design and is available for users through a link.
  • The calculator should be initialized with 0.
  • Previous operations should show above the output value (break line on long ones).
  • AC stands for "All Clear", it should clear previous operations, incoming operations as well as the output value and bring back Calculator to the initial state with 0.
  • C stands for "Clear", it should only delete the last entry.
  • Users should be able to input numbers and execute all the available operations (change signs, calculate percentage value, divide, multiply, subtract and add).
  • Users should be able to get the correct result by pressing the "=" operator and add a decimal by pressing "," (maximum one decimal in the number should be present).
  • The calculator shouldn't allow a number to begin with multiple zeros.
  • Watch out for other gotchas, e.g. multiple operations (always execute "number operation number", don't evaluate more than a single pair of numbers), round long decimals, don't allow "=" on empty input, don't let to divide by 0. You'll probably find more gotchas while coding 🙈.
Additional requirements
  • Users should be able to toggle between dark and light modes.
  • When something "wrong" happens, display a nice error message to the user. (e.g. when the user tries to divide by 0).
  • Add hover effects, animations, transitions. Experiment with it.
  • Add unit tests to your code, using e.g. jest.

How to start

In most cases, CodeSandbox will be the best place for starting out rapidly.
You could also use an IDE, VSCode for example, and create e.g. a GitHub repository with custom deployment. More about it in the "Build & Deploy" section.
First steps
  • Be Agile! Plan your work upfront either with Scrum or Kanban by creating e.g. Trello board for this project.
  • Open the design by clicking the button under the above image.
  • Get familiar with design, it contains all the assets (except icons sometimes - use e.g. fontawesome), CSS properties you'll need to use.
  • After deciding on either CodeSandbox or GitHub repo, set your project with initial files, directory structure (your own preference).
  • Nothing will stop you now. Don't forget to share a link once you completed the project!

Technologies & Tools

Core concepts

Stuck, can't progress?

Take a break, think about all the pieces you need to build for this project.
I'll be happy to assist you, try out my Mentorship or/and connect to a study group on Slack where I and mentees will be able to answer your questions.

Build & Deploy

If you decided on CodeSandbox, there should be a "Share" button that you can use as a link for your completed project.
Otherwise, for simple, static projects (HTML, CSS, JavaScript) you can try GitHub Pages. For more complex deployments (React, etc.), Netlify or Vercel should be good. If the project has a little bit of Backend, try Heroku for it.

Review & Feedback

Before you share the completed project, feel free to post it on Slack for review, someone might pick it up and give honest feedback, maybe even propose code improvements. After all, we want to improve as Developers.

Share your solution

It would be amazing if you can tweet @BigsonDev with the link to the completed project and/or GitHub repo. All the mentees would love to see what you've built (and me too).

Wall of Fame

To get in the Wall of Fame, I'll need a couple of things.
  • Link to the completed project (CodeSandbox link or completed project link with GitHub repo link).
  • Your nickname. (brand name, something spicy 🔥)
  • Portfolio/Website/GitHub link you would like to share with the world.
If I missed your solution, please, contact me via the Reach Out form.
I can't promise every solution will land on the Wall of Fame, it needs to be neat and crispy.
spread the word
Do you think this project is cool? Share it with someone!