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417.72KI
July 29, 2025
Programming
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Comparing decimals in Swift Testing
https://love-swift.connpass.com/event/361053/
417.72KI
July 29, 2025
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Transcript
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"CPVU struct Me { let name = “(redacted)” let twitter
= "417_72ki" let gitHub = "417-72KI" let workAt = "(redacted)" let job = "Software Engineer in Mobile" let communities = ["love_swift", "Chiba.swift"] }
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ςετɺॻ͍ͯ·͢ΑͶʁ
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খͷςετͷྫ ࡶ import XCTest final class SampleTests: XCTestCase { func
testExample() { let a = 0.1 let b = 0.2 XCTAssertEqual(a, 0.1) XCTAssertEqual(b, 0.2) XCTAssertEqual(a + b, 0.3) XCTAssertEqual(a - b, -0.1) XCTAssertEqual(b - a, 0.1) XCTAssertEqual(a * b, 0.02) XCTAssertEqual(a / b, 0.5) XCTAssertEqual(b / a, 2) } }
খͷςετͷྫ ࣮ߦ݁Ռ w খͷςετɺॻ͍ͯ·͔͢ʁ
🤔
খͷςετͷྫ ී௨Βͳ͍ func testExample2() { func doSomething(_ a: Int, _
b: Int) -> Int { let tmp = Double(a) / 10 + Double(b) / 10 return Int(tmp * 10) } XCTAssertEqual(doSomething(1, 7), 8) }
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ࡶʹղઆ ਐʹมͯ͠ҰఆͷॴͰؙΊΒΕΔ IUUQTUPPMTNCTZTDPNDBMDVMBUPSTJFFFQIQ
ࡶʹղઆ ਐʹมͯ͠ҰఆͷॴͰؙΊΒΕΔ IUUQTUPPMTNCTZTDPNDBMDVMBUPSTJFFFQIQ
ࡶʹղઆ ਐʹมͯ͠ҰఆͷॴͰؙΊΒΕΔ IUUQTUPPMTNCTZTDPNDBMDVMBUPSTJFFFQIQ
ුಈখͷςετ ؙΊޡࠩΛߟ্ྀͨ͠Ͱ࣮͢Δඞཁ͕͋Δ
ରॲ๏ 9$5FTUͷ߹ func testExample() { let a = 0.1 let
b = 0.2 XCTAssertEqual(a, 0.1) XCTAssertEqual(b, 0.2) XCTAssertEqual(a + b, 0.3) XCTAssertEqual(a - b, -0.1) XCTAssertEqual(b - a, 0.1) XCTAssertEqual(a * b, 0.02) XCTAssertEqual(a / b, 0.5) XCTAssertEqual(b / a, 2) }
ରॲ๏ 9$5FTUͷ߹ func testExample() { let a = 0.1 let
b = 0.2 XCTAssertEqual(a, 0.1, accuracy: 0.01) XCTAssertEqual(b, 0.2, accuracy: 0.01) XCTAssertEqual(a + b, 0.3, accuracy: 0.01) XCTAssertEqual(a - b, -0.1, accuracy: 0.01) XCTAssertEqual(b - a, 0.1, accuracy: 0.01) XCTAssertEqual(a * b, 0.02, accuracy: 0.01) XCTAssertEqual(a / b, 0.5, accuracy: 0.01) XCTAssertEqual(b / a, 2, accuracy: 0.01) }
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4XJGU5FTUJOHͷ߹ʁ
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TXJGUUFTUJOHSFWPMVUJPOBSZͰม #FGPSF import XCTest final class SwiftTestingSampleTests: XCTestCase { func
testExample() { let a = 0.1 let b = 0.2 XCTAssertEqual(a, 0.1, accuracy: 0.01) XCTAssertEqual(b, 0.2, accuracy: 0.01) XCTAssertEqual(a + b, 0.3, accuracy: 0.01) XCTAssertEqual(a - b, -0.1, accuracy: 0.01) XCTAssertEqual(b - a, 0.1, accuracy: 0.01) XCTAssertEqual(a * b, 0.02, accuracy: 0.01) XCTAssertEqual(a / b, 0.5, accuracy: 0.01) XCTAssertEqual(b / a, 2, accuracy: 0.01) } }
TXJGUUFTUJOHSFWPMVUJPOBSZͰม "GUFS import Testing @Suite struct SwiftTestingSampleTests { @Test func
example() { let a = 0.1 let b = 0.2 #expect(a == 0.1, accuracy: 0.01) #expect(b == 0.2, accuracy: 0.01) #expect(a + b == 0.3, accuracy: 0.01) #expect(a - b == -0.1, accuracy: 0.01) #expect(b - a == 0.1, accuracy: 0.01) #expect(a * b == 0.02, accuracy: 0.01) #expect(a / b == 0.5, accuracy: 0.01) #expect(b / a == 2, accuracy: 0.01) } }
TXJGUUFTUJOHSFWPMVUJPOBSZͰม "GUFS 🤮
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TXJGUOVNFSJDTΛ͏ #FGPSF import Testing @Suite struct SwiftTestingSampleTests { @Test func
example() { let a = 0.1 let b = 0.2 #expect(a == 0.1, accuracy: 0.01) #expect(b == 0.2, accuracy: 0.01) #expect(a + b == 0.3, accuracy: 0.01) #expect(a - b == -0.1, accuracy: 0.01) #expect(b - a == 0.1, accuracy: 0.01) #expect(a * b == 0.02, accuracy: 0.01) #expect(a / b == 0.5, accuracy: 0.01) #expect(b / a == 2, accuracy: 0.01) } }
TXJGUOVNFSJDTΛ͏ "GUFS import Testing import Numerics @Suite struct SwiftTestingSampleTests {
@Test func example() { let a = 0.1 let b = 0.2 #expect(a.isApproximatelyEqual(to: 0.1, relativeTolerance: 0.01)) #expect(b.isApproximatelyEqual(to: 0.2, relativeTolerance: 0.01)) #expect((a + b).isApproximatelyEqual(to: 0.3, relativeTolerance: 0.01)) #expect((a - b).isApproximatelyEqual(to: -0.1, relativeTolerance: 0.01)) #expect((b - a).isApproximatelyEqual(to: 0.1, relativeTolerance: 0.01)) #expect((a * b).isApproximatelyEqual(to: 0.02, relativeTolerance: 0.01)) #expect((a / b).isApproximatelyEqual(to: 0.5, relativeTolerance: 0.01)) #expect((b / a).isApproximatelyEqual(to: 2, relativeTolerance: 0.01)) } }
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FYQSFTTJPOͱFYQSFTTJPOͷ ͕ࠩBDDVSBDZҎԼͳΒ0,
࠷ऴతʹ ͜ΕΛ import XCTest final class SwiftTestingSampleTests: XCTestCase { func
testExample() { let a = 0.1 let b = 0.2 XCTAssertEqual(a, 0.1, accuracy: 0.01) XCTAssertEqual(b, 0.2, accuracy: 0.01) XCTAssertEqual(a + b, 0.3, accuracy: 0.01) XCTAssertEqual(a - b, -0.1, accuracy: 0.01) XCTAssertEqual(b - a, 0.1, accuracy: 0.01) XCTAssertEqual(a * b, 0.02, accuracy: 0.01) XCTAssertEqual(a / b, 0.5, accuracy: 0.01) XCTAssertEqual(b / a, 2, accuracy: 0.01) } }
࠷ऴతʹ ͜͏ͯ͠ import Testing @Suite struct SwiftTestingSampleTests { @Test func
example() { let a = 0.1 let b = 0.2 #expect(a == 0.1, accuracy: 0.01) #expect(b == 0.2, accuracy: 0.01) #expect(a + b == 0.3, accuracy: 0.01) #expect(a - b == -0.1, accuracy: 0.01) #expect(b - a == 0.1, accuracy: 0.01) #expect(a * b == 0.02, accuracy: 0.01) #expect(a / b == 0.5, accuracy: 0.01) #expect(b / a == 2, accuracy: 0.01) } }
࠷ऴతʹ ͜͏͡Ό import Testing @Suite struct SwiftTestingSampleTests { @Test func
example() { let a = 0.1 let b = 0.2 #expect(abs(a - 0.1) < 0.01) #expect(abs(b - 0.2) < 0.01) #expect(abs(a + b - 0.3) < 0.01) #expect(abs(a - b - -0.1) < 0.01) #expect(abs(b - a - 0.1) < 0.01) #expect(abs(a * b - 0.02) < 0.01) #expect(abs(a / b - 0.5) < 0.01) #expect(abs(b / a - 2) < 0.01) } }
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