Codehs 8.1.5 Manipulating 2d Arrays <Premium × HOW-TO>

var array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]; array[1][1] = 10; // update element at row 1, column 1 console.log(array); // output: [[1, 2, 3], [4, 10, 6], [7, 8, 9]] To add a new row to a 2D array, you can use the push() method.

var array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]; array[1][1] = 10; // update element at row 1, column 1 console.log(array); // output: [[1, 2, 3], [4, 10, 6], [7, 8, 9]] To add a new row to a 2D array, you can use the push() method.

Changelog

Version 1.2.0

November 6, 2025
  • 🎨 New: 8 beautiful themes added (Classic, Dark Mode, Ocean Breeze, Forest Green, Sunset Glow, Neon Lights, Pastel Dream, and more)
  • 🌙 Auto Dark Mode: Theme automatically adapts to your device's dark mode preference
  • 🎯 Visual Theme Switcher: Quick-access circular buttons to instantly switch between themes
  • 🧩 New Constraints: Added Even (E), Odd (O), No 6s (∅6), Product (×), and Prime (P) constraints for more puzzle variety
  • 🔧 Fixed: Resolved "New Game" button error when switching between puzzles

Version 1.1.0

October 2, 2025
  • New: 150 additional puzzles added to the game collection
  • ⚙️ Settings: Added notifications toggle to show/hide gameplay feedback messages
  • 📊 Progress Tracking: New option to mark games as "Played" for progress tracking
  • 🎯 Smart Game Selection: Filter played games from "New Game" button selection
  • 🔧 Improved: Settings now apply immediately without requiring page refresh