Frontend Mentor - Connect Four game solution

This is a solution to the Connect Four game challenge on Frontend Mentor. Frontend Mentor challenges help you improve your coding skills by building realistic projects.

Table of contents

• Overview
  • The challenge
  • Screenshot
  • Links
• My process
  • Built with
  • What I learned
  • Continued development
• Author

Overview

The challenge

Users should be able to:

• View the game rules
• Play a game of Connect Four against another human player (alternating turns on the same computer)
• View the optimal layout for the interface depending on their device's screen size
• See hover and focus states for all interactive elements on the page
• Bonus: See the discs animate into their position when a move is made
• Bonus: Play against the computer

Screenshot

Links

• Solution URL: GitHub Repository
• Live Site URL: Live Demo

My process

Built with

• Semantic HTML5 markup
• CSS custom properties
• CSS Modules
• CSS Grid
• Mobile-first workflow
• SolidJS - JS library
• Vite - Build tool
• TypeScript - For type safety
• SolidJS Router - Client-side routing

What I learned

This project helped me explore SolidJS's reactive primitives and signals. I implemented a complete Connect Four game with:

• Game Logic: 6x7 board matrix with win detection for horizontal, vertical, and diagonal connections
• Turn Timer: 30-second countdown per turn with automatic forfeit
• Score Tracking: Persistent scores throughout multiple rounds
• Winning Animation: Visual highlighting of winning disc sequences

Key implementation highlights:

const checkWin = (board: Cell[][], row: number, col: number, player: number): boolean => {
  // Check all four directions: horizontal, vertical, and both diagonals
  // Returns true if 4 or more consecutive pieces are found
}

// Timer management with SolidJS effects
createEffect(() => {
  if (gameState() !== 'playing' || !isTimerActive()) return
  
  const timer = setInterval(() => {
    setTimeLeft(prev => {
      if (prev <= 1) {
        const otherPlayer = currentPlayer() === 1 ? 2 : 1
        handleWin(otherPlayer)
        return 30
      }
      return prev - 1
    })
  }, 1000)

  return () => clearInterval(timer)
})

Continued development

Future enhancements to focus on:

• AI Opponent: Implement minimax algorithm for computer player
• Disc Animations: Add smooth drop animations when pieces are placed
• Sound Effects: Audio feedback for moves and wins
• Online Multiplayer: Real-time gameplay between remote players
• Accessibility: Enhanced keyboard navigation and screen reader support

Author

• Frontend Mentor - @yourusername
• GitHub - @yourusername