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# fdemircan's solution

## to Leap in the Swift Track

Published at Apr 23 2021 · 0 comments
Instructions
Test suite
Solution

Given a year, report if it is a leap year.

The tricky thing here is that a leap year in the Gregorian calendar occurs:

``````on every year that is evenly divisible by 4
except every year that is evenly divisible by 100
unless the year is also evenly divisible by 400
``````

For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap year, but 2000 is.

If your language provides a method in the standard library that does this look-up, pretend it doesn't exist and implement it yourself.

## Notes

Though our exercise adopts some very simple rules, there is more to learn!

For a delightful, four minute explanation of the whole leap year phenomenon, go watch this youtube video.

## Setup

Go through the project setup instructions for Xcode using Swift:

http://exercism.io/languages/swift
http://exercism.io/languages/swift/tests

Notably from the source directory:

`swift test` runs tests
`swift package generate-xcodeproj` creates an Xcode project

## Source

JavaRanch Cattle Drive, exercise 3 http://www.javaranch.com/leap.jsp

## Submitting Incomplete Solutions

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

### LeapTests.swift

``````import XCTest
@testable import Leap

class LeapTests: XCTestCase {

func testVanillaLeapYear() {
let year = Year(calendarYear: 1996)
XCTAssertTrue(year.isLeapYear)
}

func testAnyOldYear() {
let year = Year(calendarYear: 1997)
XCTAssertFalse(year.isLeapYear)
}

func testCentury() {
let year = Year(calendarYear: 1900)
XCTAssertFalse(year.isLeapYear)
}

func testExceptionalCentury() {
let year = Year(calendarYear: 2400)
XCTAssertTrue(year.isLeapYear)
}

static var allTests: [(String, (LeapTests) -> () throws -> Void)] {
return [
("testVanillaLeapYear", testVanillaLeapYear),
("testAnyOldYear", testAnyOldYear),
("testCentury", testCentury),
("testExceptionalCentury", testExceptionalCentury),
]
}
}``````

### LinuxMain.swift

``````import XCTest
@testable import LeapTests

XCTMain([
testCase(LeapTests.allTests),
])``````
``````//Solution goes in Sources

struct Year {
var calendarYear: Int
var isLeapYear: Bool

init(calendarYear: Int) {
self.calendarYear = calendarYear

if (calendarYear % 4 == 0 && calendarYear % 100 != 0) ||
(calendarYear % 400 == 0){
self.isLeapYear =  true
}
else {
self.isLeapYear = false
}
}
}``````

### What can you learn from this solution?

A huge amount can be learned from reading other peopleâ€™s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

• What compromises have been made?