# mbraak's solution

## to Space Age in the Objective-C Track

Published at Apr 22 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.

## Setup

There are two different methods of getting set up to run the tests with Objective-C:

• Create an Xcode project with a test target which will run the tests.
• Use the ruby gem `objc` as a test runner utility.

Both are described in more detail here: http://exercism.io/languages/objective-c

### Submitting Exercises

When submitting an exercise, make sure your solution file is in the same directory as the test code.

The submit command will look something like:

``````exercism submit <path-to-exercism-workspace>/objective-c/space-age/SpaceAge.m
``````

You can find the Exercism workspace by running `exercism debug` and looking for the line beginning with Workspace.

## 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.m

``````#import <XCTest/XCTest.h>

#if __has_include("SpaceAgeExample.h")
# import "SpaceAgeExample.h"
# else
# import "SpaceAge.h"
#endif

NS_ASSUME_NONNULL_BEGIN

@interface SpaceAgeTest : XCTestCase

@end

@implementation SpaceAgeTest

static const double AgeAccuracy = 0.01;

- (void)testAgeInSeconds {
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:1000000];
XCTAssertEqual(1000000, age.seconds);
}

- (void)testAgeInEarthYears { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:1000000000];
XCTAssertEqualWithAccuracy(31.69, age.onEarth, AgeAccuracy);
}

- (void)testAgeInMercuryYears { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:2134835688];
XCTAssertEqualWithAccuracy(67.65, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(280.88, age.onMercury, AgeAccuracy);
}

- (void)testAgeInVenusYears { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:189839836];
XCTAssertEqualWithAccuracy(6.02, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(9.78, age.onVenus, AgeAccuracy);
}

- (void)testAgeOnMars { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:2329871239];
XCTAssertEqualWithAccuracy(73.83, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(39.25, age.onMars, AgeAccuracy);
}

- (void)testAgeOnJupiter { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:901876382];
XCTAssertEqualWithAccuracy(28.58, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(2.41, age.onJupiter, AgeAccuracy);
}

- (void)testAgeOnSaturn { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:3000000000];
XCTAssertEqualWithAccuracy(95.06, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(3.23, age.onSaturn, AgeAccuracy);
}

- (void)testAgeOnUranus { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:3210123456];
XCTAssertEqualWithAccuracy(101.72, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(1.21, age.onUranus, AgeAccuracy);
}

- (void)testAgeOnNeptune { //!OCLINT
SpaceAge *age = [[SpaceAge alloc] initWithSeconds:8210123456];
XCTAssertEqualWithAccuracy(260.16, age.onEarth, AgeAccuracy);
XCTAssertEqualWithAccuracy(1.58, age.onNeptune, AgeAccuracy);
}

@end
NS_ASSUME_NONNULL_END``````

### SpaceAge.m

``````#import "SpaceAge.h"

@implementation SpaceAge
- (id) initWithSeconds: (long) seconds {
self = [super init];

_seconds = seconds;
_onEarth = seconds / 31557600.0;
_onMercury = _onEarth / 0.2408467;
_onVenus = _onEarth / 0.61519726;
_onMars = _onEarth / 1.8808158;
_onJupiter = _onEarth / 11.862615;
_onSaturn = _onEarth / 29.447498;
_onUranus = _onEarth / 84.016846;
_onNeptune = _onEarth / 164.79132;

return self;
}
@end``````

### SpaceAge.h

``````#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface SpaceAge : NSObject
@property long seconds;
@property double onEarth;
@property double onMercury;
@property double onVenus;
@property double onMars;
@property double onJupiter;
@property double onSaturn;
@property double onUranus;
@property double onNeptune;

- (id) initWithSeconds: (long) seconds;
@end

NS_ASSUME_NONNULL_END``````