Get Programming with JavaScript

Get Programming with JavaScript - Listing 10.11

Listing 10.11 - A map with four locations

var Place = function (title, description) {
    this.title = title;
    this.exits = {};

    this.addExit = function (direction, exit) {
        this.exits[direction] = exit;
    };

    this.showExits = function () {
        console.log("Exits from " + this.title + ":");

        Object.keys(this.exits).forEach(function (key) {
            console.log(key);
        });
    };
};

var library = new Place("The Old Library");
var kitchen = new Place("The Kitchen");
var garden = new Place("The Kitchen Garden");
var cupboard = new Place("The Kitchen Cupboard");

library.addExit("north", kitchen);
garden.addExit("east", kitchen);
cupboard.addExit("west", kitchen);

kitchen.addExit("south", library);
kitchen.addExit("west", garden);
kitchen.addExit("east", cupboard);

library.showExits();
kitchen.showExits();

Further Adventures

Listing 10.11 - A map with four locations - Tasks 1 to 4

Update the Place constructor to include an items array assigned as a property of the this object.
Add an addItem method to the constructor that lets you add items to the items array.
Add a showItems method to the constructor that displays the items in the items array.
Test your work by adding items to the different locations and displaying the items on the console.

var Place = function (title, description) {
    this.title = title;
    this.exits = {};
    this.items = [];

    this.addExit = function (direction, exit) {
        this.exits[direction] = exit;
    };

    this.showExits = function () {
        console.log("Exits from " + this.title + ":");

        Object.keys(this.exits).forEach(function (key) {
            console.log(key);
        });
    };

    this.addItem = function (item) {
        this.items.push(item);
    };

    this.showItems = function () {
        console.log("Items in " + this.title + ":");

        this.items.forEach(function (item) {
            console.log("  - " + item);
        });
    };
};

var library = new Place("The Old Library");
var kitchen = new Place("The Kitchen");
var garden = new Place("The Kitchen Garden");
var cupboard = new Place("The Kitchen Cupboard");

library.addExit("north", kitchen);
garden.addExit("east", kitchen);
cupboard.addExit("west", kitchen);

kitchen.addExit("south", library);
kitchen.addExit("west", garden);
kitchen.addExit("east", cupboard);

library.showExits();
kitchen.showExits();

library.addItem("a rusty key");
kitchen.addItem("a smelly cheese");
kitchen.addItem("holy water");

library.showItems();
kitchen.showItems();