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billwanjohi's solution

to Space Age in the Scala Track

Published at Feb 04 2019 · 0 comments
Test suite

Given an age in seconds, calculate how old someone would be on:

  • Earth: orbital period 365.25 Earth days, or 31557600 seconds
  • Mercury: orbital period 0.2408467 Earth years
  • Venus: orbital period 0.61519726 Earth years
  • Mars: orbital period 1.8808158 Earth years
  • Jupiter: orbital period 11.862615 Earth years
  • Saturn: orbital period 29.447498 Earth years
  • Uranus: orbital period 84.016846 Earth years
  • Neptune: orbital period 164.79132 Earth years

So if you were told someone were 1,000,000,000 seconds old, you should be able to say that they're 31.69 Earth-years old.

If you're wondering why Pluto didn't make the cut, go watch this youtube video.

The Scala exercises assume an SBT project scheme. The exercise solution source should be placed within the exercise directory/src/main/scala. The exercise unit tests can be found within the exercise directory/src/test/scala.

To run the tests simply run the command sbt test in the exercise directory.

For more detailed info about the Scala track see the help page.


Partially inspired by Chapter 1 in Chris Pine's online Learn to Program tutorial. http://pine.fm/LearnToProgram/?Chapter=01

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.


import org.scalatest.{Matchers, FunSuite}

/** @version 1.1.0 */
class SpaceAgeTest extends FunSuite with Matchers {

  test("age on Earth") {
    SpaceAge.onEarth(1000000000) should be (31.69 +- 0.01)

  test("age on Mercury") {
    SpaceAge.onMercury(2134835688) should be (280.88 +- 0.01)

  test("age on Venus") {
    SpaceAge.onVenus(189839836) should be (9.78 +- 0.01)

  test("age on Mars") {
    SpaceAge.onMars(2.329871239E9) should be (39.25 +- 0.01)

  test("age on Jupiter") {
    SpaceAge.onJupiter(901876382) should be (2.41 +- 0.01)

  test("age on Saturn") {
    SpaceAge.onSaturn(3.0E9) should be (3.23 +- 0.01)

  test("age on Uranus") {
    SpaceAge.onUranus(3.210123456E9) should be (1.21 +- 0.01)

  test("age on Neptune") {
    SpaceAge.onNeptune(8.210123456E9) should be (1.58 +- 0.01)
object SpaceAge {
  def onEarth(seconds: Double) = seconds / 31557600
  def onMercury(seconds: Double) = onEarth(seconds) / 0.2408467
  def onVenus(seconds: Double) = onEarth(seconds) / 0.61519726
  def onMars(seconds: Double) = onEarth(seconds) / 1.8808158
  def onJupiter(seconds: Double) = onEarth(seconds) / 11.862615
  def onSaturn(seconds: Double) = onEarth(seconds) / 29.447498
  def onUranus(seconds: Double) = onEarth(seconds) / 84.016846
  def onNeptune(seconds: Double) = onEarth(seconds) / 164.79132

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