Get Programming with JavaScript

Get Programming with JavaScript - Listing 9.05

Listing 9.05 - Including a moons array in our Planet constructor

var Planet = function (name, position, type) {
    this.name = name;
    this.position = position;
    this.type = type;
    this.moons = [];

    this.showPlanet = function () {
        var info = this.name + ": planet " + this.position;
        info +=  " - " + this.type;
        console.log(info);
        console.log("Moons: " + this.moons.join(', ') + ".");
    };

    this.addMoon = function (moon) {
        this.moons.push(moon);
    };
};

var planet = new Planet( "Jupiter", 5, "Gas Giant" );

planet.addMoon("Io");
planet.addMoon("Europa");

planet.showPlanet();

Further Adventures

Listing 9.05 - Including a moons array in our Planet constructor - Tasks 1, 2 & 3

Create a second planet. Make one up if you like.
Add three moons to the second planet.
Call the showPlanet method on the second planet.

var Planet = function (name, position, type) {
    this.name = name;
    this.position = position;
    this.type = type;
    this.moons = [];

    this.showPlanet = function () {
        var info = this.name + ": planet " + this.position;
        info +=  " - " + this.type;
        console.log(info);
        console.log("Moons: " + this.moons.join(', ') + ".");
    };

    this.addMoon = function (moon) {
        this.moons.push(moon);
    };
};

var planet = new Planet( "Jupiter", 5, "Gas Giant" );

planet.addMoon("Io");
planet.addMoon("Europa");

planet.showPlanet();


// create a second planet
var planet2 = new Planet( "Barxon", 3, "Cheese Giant" );

// add three moons
planet2.addMoon("Cheddax");
planet2.addMoon("Filboid");
planet2.addMoon("Studge");

// display the planet
planet2.showPlanet();

Listing 9.05 - Including a moons array in our Planet constructor - Task 4

Add a removeMoon method that removes the last moon from the moons array.

var Planet = function (name, position, type) {
    this.name = name;
    this.position = position;
    this.type = type;
    this.moons = [];

    this.showPlanet = function () {
        var info = this.name + ": planet " + this.position;
        info +=  " - " + this.type;
        console.log(info);
        console.log("Moons: " + this.moons.join(', ') + ".");
    };

    this.addMoon = function (moon) {
        this.moons.push(moon);
    };

    // add the new method
    this.removeMoon = function () {
        this.moons.pop();
    };
};