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# SergiiVlasiuk's solution

## to Space Age in the Scala Track

Published at Jan 28 2019 · 0 comments
Instructions
Test suite
Solution

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.

## Source

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.

### SpaceAgeTest.scala

``````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") {
pending
SpaceAge.onMercury(2134835688) should be (280.88 +- 0.01)
}

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

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

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

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

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

test("age on Neptune") {
pending
SpaceAge.onNeptune(8.210123456E9) should be (1.58 +- 0.01)
}
}``````
``````trait SolarPlanet {
def coefficient(): Double
def yearSeconds = 31557600 * coefficient()
}
object Earth extends SolarPlanet {
def coefficient = 1.0
}
object Mercury extends SolarPlanet {
def coefficient = 0.2408467
}
object Venus extends SolarPlanet {
def coefficient = 0.61519726
}
object Mars extends SolarPlanet {
def coefficient = 1.8808158
}
object Jupiter extends SolarPlanet {
def coefficient = 11.862615
}
object Saturn extends SolarPlanet {
def coefficient = 29.447498
}
object Uranus extends SolarPlanet {
def coefficient = 84.016846
}
object Neptune extends SolarPlanet {
def coefficient = 164.79132
}

object SpaceAge {
private val onX = (s: Double, p: SolarPlanet) => s / p.yearSeconds

def onEarth(seconds: Double): Double = onX(seconds, Earth)
def onMercury(seconds: Double): Double = onX(seconds, Mercury)
def onVenus(seconds: Double): Double = onX(seconds, Venus)
def onMars(seconds: Double): Double = onX(seconds, Mars)
def onJupiter(seconds: Double): Double = onX(seconds, Jupiter)
def onSaturn(seconds: Double): Double = onX(seconds, Saturn)
def onUranus(seconds: Double): Double = onX(seconds, Uranus)
def onNeptune(seconds: Double): Double = onX(seconds, Neptune)
}``````