React Tutorial: Build a Calculator App from Scratch

This tutorial guides you through building a React calculator app. You'll learn wireframing, layout design, component creation, state updates, and output formatting. A deployed project link and source code are provided for reference.

Key Concepts Covered:

• Wireframing and Design: Start with a basic wireframe (using Figma or similar) to define component structure before styling.
• Project Setup: Use npx create-react-app for quick project initialization, then clean up the default files.
• Component Organization: Structure the app with components: Wrapper, Screen, ButtonBox, and Button, each with its CSS.
• State Management: Use React state and handlers for calculations ( , -, *, /), reset, and value inversion.
• Input/Output Formatting: Format numbers with separators and handle multiple decimal points.
• Component Interaction: Ensure seamless interaction between components for a functional app.

Planning and Design:

The calculator will include:

• Basic arithmetic operations ( , -, *, /)
• Decimal support
• Percentage calculation
• Value inversion ( /-)
• Reset functionality
• Number formatting for large numbers
• Dynamic output resizing

A wireframe is essential for planning the layout and identifying components. Color schemes are less important at this stage.

A visually appealing color scheme is crucial:

• Wrapper should contrast with the background.
• Screen and button values should be easily readable.
• The equals button should have an accent color.

Project Setup and Component Creation:

Create the React project:

<code class="language-bash">npx create-react-app calculator
cd calculator</code>

Clean up the src folder, keeping only App.js, index.css, and index.js. Create a components folder within src and the necessary files for each component (Wrapper.js, Wrapper.css, etc.).

Component Implementation (Examples):

• Wrapper.js: A container for the calculator, providing centering and styling.
• Screen.js: Displays the calculated values, using react-textfit for dynamic resizing.
• ButtonBox.js: A container for the buttons.
• Button.js: Individual calculator buttons with onClick handlers.

(Note: The full code for each component and handler function is lengthy and omitted here for brevity. Refer to the original input for complete code.)

Functionality and State Management:

Use useState to manage the calculator's state (num, sign, res). Implement handler functions (numClickHandler, signClickHandler, equalsClickHandler, etc.) to update the state based on button clicks. The equalsClickHandler performs the actual calculations.

Input Formatting:

Use the provided toLocaleString and removeSpaces functions to format numbers with thousands separators and handle spaces appropriately.

Testing and Deployment:

Thorough testing is crucial. Deployment can be done using platforms like Netlify, Vercel, or GitHub Pages.

FAQs (Summary):

The FAQs section covers setting up the project, key components, handling user input and calculations, error handling, styling, testing, deployment, adding features, and using external libraries. Refer to the original input for detailed answers.

Remember to consult the original input for the complete code and detailed explanations of each function. This response provides a streamlined overview of the tutorial.

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