Build a Sudoku Game with React.js

How to Create a Sudoku Game Using React.js

Sudoku is a popular number puzzle game that challenges players to fill a 9x9 grid so that each column, each row, and each of the nine 3x3 grids contain all the digits from 1 to 9. In this blog, we'll build a Sudoku game using React.js, a popular JavaScript library for building user interfaces.

Step 1: Set Up Your React Environment

First, ensure you have Node.js installed on your machine. If not, download and install it from nodejs.org. Then, use the following command to create a new React application:

npx create-react-app sudoku-game
cd sudoku-game
npm start

This will set up a new React application and start the development server.

Step 2: Plan Your Components

For a Sudoku game, you will need at least the following components:

App: The main component that will hold the entire game.
Board: This component will display the 9x9 grid.
Cell: Each cell in the grid will be a separate component.

Step 3: Create the Cell Component

Create a Cell.js file in the src directory:

// src/Cell.js
import React from 'react';

const Cell = ({ value, onChange }) => {
return (
<input
type="text"
className="cell"
value={value}
onChange={onChange}
maxLength="1"
/>
);
};

export default Cell;

Step 4: Create the Board Component

Create a Board.js file in the src directory:

// src/Board.js
import React from 'react';
import Cell from './Cell';

const Board = ({ board, onCellChange }) => {
return (
<div className="board">
{board.map((row, rowIndex) => (
<div key={rowIndex} className="row">
{row.map((cell, colIndex) => (
<Cell
key={colIndex}
value={cell}
onChange={(e) => onCellChange(rowIndex, colIndex, e.target.value)}
/>
))}
</div>
))}
</div>
);
};

export default Board;

Step 5: Implement the App Component

Update the App.js file to include the Board component and handle the state of the game:

// src/App.js
import React, { useState } from 'react';
import Board from './Board';
import './App.css';

const initialBoard = [
// 9x9 array with initial values (0 represents empty cells)
];

const App = () => {
const [board, setBoard] = useState(initialBoard);

const handleCellChange = (row, col, value) => {
const newBoard = [...board];
newBoard[row][col] = parseInt(value) || 0;
setBoard(newBoard);
};

return (
<div className="app">
<h1>Sudoku Game</h1>
<Board board={board} onCellChange={handleCellChange} />
</div>
);
};

export default App;

Step 6: Add Basic Styling

Create an App.css file to add some basic styling:

/ src/App.css /
.app {
text-align: center;
margin: 20px;
}

.board {
display: grid;
grid-template-columns: repeat(9, 40px);
gap: 2px;
}

.row {
display: contents;
}

.cell {
width: 40px;
height: 40px;
text-align: center;
font-size: 20px;
border: 1px solid #ccc;
}

.cell:focus {
outline: none;
border: 2px solid #00f;
}

Step 7: Add Initial Board Data

You can define an initial Sudoku board in App.js:

const initialBoard = [
[5, 3, 0, 0, 7, 0, 0, 0, 0],
[6, 0, 0, 1, 9, 5, 0, 0, 0],
[0, 9, 8, 0, 0, 0, 0, 6, 0],
[8, 0, 0, 0, 6, 0, 0, 0, 3],
[4, 0, 0, 8, 0, 3, 0, 0, 1],
[7, 0, 0, 0, 2, 0, 0, 0, 6],
[0, 6, 0, 0, 0, 0, 2, 8, 0],
[0, 0, 0, 4, 1, 9, 0, 0, 5],
[0, 0, 0, 0, 8, 0, 0, 7, 9]
];

Step 8: Validate the Sudoku Board

Implement a function to validate the Sudoku board. Add this logic to the App.js file:

Step 9: Testing and Final Touches

Ensure all functionality works correctly.
Style the components to make the game visually appealing.
Add more features like hints or difficulty levels if desired.

Conclusion

Building a Sudoku game in React.js is a rewarding project that covers essential concepts such as component-based architecture, state management, and user interaction handling. This guide provides a foundation, and you can extend it with more features to enhance the gameplay experience.

Step-by-Step Guide to Building a Sudoku Game with React.js

Building a Sudoku Game with React.js: A Simple Guide

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