An NPM package for human vs human or human vs computer play for the game Connect 4 aka Four in a row.

Install

Install this package with npm i connectfourai or npm install connectfourai.

Setup

// Load the module and store it in a variable.
const AI = require("connectfourai");

Usage

const AI = require("connectfourai");

// To start a new game.
AI.new_game();

// To see the board.
AI.display_board();

// Makes a move for the player. Note that columns are 0-indexed, so if you want the first column then use 0, and if you want the last column use 6.
AI.play_human(4);

// Makes a move for the AI.
AI.play_ai();
AI.play_ai(2); /* You can also specify a column for the AI to play in. */
// You can also specify a depth to play against. The higher the number, the longer the bot will take to calculate. A depth of 9 is suggested.
AI.play_ai(null, 4);

// To check if a column can be played.
AI.can_play(3);

// To see which columns can be played in.
AI.get_valid_locations();

// To see which column is the best for a human to play. Can be used as a hint.
AI.get_best_move();
AI.get_best_move(5); /* You can specify a depth as well */

Built-in variables

For information on the state of the game.

COLORS                          // A collection of unicode colors to choose from.
COLORS.blue                     // One example.
GAME.full                       // If the board is full.
GAME.history                    // A history of moves played so far. Format is { column: 3, piece: "🟡" }
GAME.over                       // If the game is over (full or someone won).
GAME.victor or GAME.winner      // Who won the game.
GAME.won                        // If someone won the game.

Customization

const AI = require("connectfourai");

// If desired, customize the pieces. They can be anything you want!
AI.set_ai_piece("⚪");          // Default: ⚫
AI.set_player_piece("🔵");      // Default: 🔴
AI.set_empty_piece("🟢");       // Default: 🟡

// You can also use the provided color object.
AI.set_ai_piece(COLORS.white);
AI.set_player_piece(COLORS.blue);
AI.set_empty_piece(COLORS.green);

// You can change the rows, columns, and even the connect length.
AI.set("columns", 10);          // Minimum 3
AI.set("rows", 9);              // Minimum 3
AI.set("depth", 5);             // Minimum 1, default 9. Change here to not have to specify as an argument later.

// You can setup a specific position. The board is setup by placing a piece in each column, from left-to-right.
AI.set_pos("4,4,4,4,4,3,3,3,6");

// Get the current position.
AI.get_pos();