Build a Simple Yet Powerful Online Calculator App
Learn how to perform calculations, manage user input, and style UI elements by building a responsive calculator using HTML, CSS, and JavaScript.A calculator app introduces fundamental JavaScript concepts like functions, events, DOM manipulation, and expression evaluation. It’s ideal for beginners looking to apply logic to real-world interfaces.
Make your calculator responsive and intuitive. Ensure it handles numeric input, basic operators, clear/delete actions, and real-time expression updates.
Responsive Number Pad
Create clickable buttons for digits, decimal points, and operators using HTML and CSS.
Live Expression Input
Display user inputs in a live expression field, updating as users click on keys.
Expression Evaluation
Use JavaScript logic or eval to compute the result when the user presses equals (=).
Clear & Backspace Options
Add functionality to clear the current input or remove the last character.
Users input values by clicking buttons on the calculator interface. The app tracks the input and calculates the result dynamically when the equals button is pressed.
- Each button click adds the character to a display field.
- Pressing '=' evaluates the expression and displays the result.
- 'C' clears the full display while '⌫' removes the last entry.
- Optional: Keyboard support allows input using physical keys.
- Optional: Add scientific features like sin, cos, log, etc.
Frontend
HTML, CSS, and Vanilla JavaScript for UI and logic
Logic Layer
JavaScript functions for parsing expressions, validation, and calculation
Optional Enhancements
Add keyboard support or advanced operators using Math library
Hosting
Deploy with GitHub Pages, Netlify, or Vercel for easy sharing
1. Design Calculator Layout
Create HTML structure with display area and numeric/operator buttons in a grid layout.
2. Style the UI
Apply CSS styles to design a visually appealing and responsive layout.
3. Add Event Listeners
Use JavaScript to detect button clicks and update the expression in the display field.
4. Evaluate Expressions
Implement logic to compute the result of the expression entered by the user.
5. Clear and Delete Functions
Add support for clearing the full expression or removing one character at a time.
Ready to Build Your Own Calculator?
Start building your Online Calculator App and strengthen your JavaScript, layout, and event-handling skills today!
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