Swiftでの文字列補間と数値演算を活用した効率的なコード作成法

let name = "Alice"
let age = 30
print("My name is \(name) and I am \(age) years old.")

let length = 5
let width = 10
let area = length * width
print("The area of the rectangle is \(length * width) square units.")

let score = 85
print("Your grade is \(score >= 90 ? "A" : "B")")

let price = 1234.56789
print("The price is \(String(format: "%.2f", price)) dollars.")

let largeNumber = 123456789.0
let formatter = NumberFormatter()
formatter.numberStyle = .currency
formatter.locale = Locale(identifier: "en_US")
if let formattedNumber = formatter.string(from: NSNumber(value: largeNumber)) {
    print("The total amount is \(formattedNumber).")
}

let successRate = 0.8567
print("The success rate is \(String(format: "%.2f", successRate * 100))%.")

let radius = 7.0
let area = 3.14159 * radius * radius
print("The area of a circle with radius \(radius) is \(area).")

The area of a circle with radius 7.0 is 153.93791.

let length = 10
let width = 5
let perimeter = (length + width) * 2
let area = length * width
print("The perimeter is \(perimeter) and the area is \(area).")

The perimeter is 30 and the area is 50.

let score = 92
print("Your score is \(score). \(score >= 90 ? "Excellent!" : "Keep trying!")")

Your score is 92. Excellent!

import Foundation

let a = 5.0
let b = 12.0
let c = 13.0

let perimeter = a + b + c
let s = perimeter / 2
let area = sqrt(s * (s - a) * (s - b) * (s - c))

print("For a triangle with sides \(a), \(b), and \(c):")
print("The perimeter is \(perimeter) units.")
print("The area is \(String(format: "%.2f", area)) square units.")

For a triangle with sides 5.0, 12.0, and 13.0:
The perimeter is 30.0 units.
The area is 30.00 square units.

let items = [("Apple", 3, 120), ("Banana", 2, 80), ("Orange", 5, 60)]
var totalCost = 0

for (item, quantity, price) in items {
    let cost = quantity * price
    totalCost += cost
    print("\(item): \(quantity) units at \(price) yen each, total: \(cost) yen")
}

print("Total cost for all items: \(totalCost) yen")

Apple: 3 units at 120 yen each, total: 360 yen
Banana: 2 units at 80 yen each, total: 160 yen
Orange: 5 units at 60 yen each, total: 300 yen
Total cost for all items: 820 yen

import Foundation

let currentDate = Date()
let futureDate = Calendar.current.date(byAdding: .day, value: 7, to: currentDate)!

let formatter = DateFormatter()
formatter.dateStyle = .full

print("Today's date is \(formatter.string(from: currentDate)).")
print("The date 7 days from now is \(formatter.string(from: futureDate)).")

Today's date is Thursday, September 26, 2024.
The date 7 days from now is Thursday, October 3, 2024.

let dividend = 10
let divisor = 0

if divisor != 0 {
    print("The result is \(dividend / divisor).")
} else {
    print("Error: Division by zero is not allowed.")
}

Error: Division by zero is not allowed.

let input: String? = "42"
if let number = Int(input ?? "") {
    print("The number is \(number).")
} else {
    print("Error: Invalid input. Could not convert to a number.")
}

The number is 42.

Error: Invalid input. Could not convert to a number.

enum CalculationError: Error {
    case divisionByZero
}

func divide(_ a: Int, by b: Int) throws -> Int {
    if b == 0 {
        throw CalculationError.divisionByZero
    }
    return a / b
}

do {
    let result = try divide(10, by: 0)
    print("Result: \(result)")
} catch CalculationError.divisionByZero {
    print("Error: Division by zero.")
} catch {
    print("Unexpected error: \(error).")
}

Error: Division by zero.

func process(data: String?) {
    guard let validData = data else {
        print("Error: Received nil data.")
        return
    }
    print("Processing data: \(validData)")
}

process(data: nil)

Error: Received nil data.

import SwiftUI

struct ContentView: View {
    @State private var value1: Double = 0
    @State private var value2: Double = 0

    var result: Double {
        value1 + value2
    }

    var body: some View {
        VStack {
            Text("Enter two numbers:")
            TextField("Value 1", value: $value1, format: .number)
                .padding()
                .keyboardType(.decimalPad)
            TextField("Value 2", value: $value2, format: .number)
                .padding()
                .keyboardType(.decimalPad)

            Text("The sum is \(result)")
                .font(.title)
                .padding()
        }
        .padding()
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

import SwiftUI

struct ContentView: View {
    @State private var score: Int = 50

    var body: some View {
        VStack {
            Slider(value: $score, in: 0...100)
                .padding()

            Text("Your score is \(score)")
                .font(.title)
                .padding()

            if score >= 75 {
                Text("Great job!")
                    .foregroundColor(.green)
                    .font(.headline)
            } else {
                Text("Keep trying!")
                    .foregroundColor(.red)
                    .font(.headline)
            }
        }
        .padding()
    }
}

Your score is 85
Great job!

import SwiftUI

struct Item: Identifiable {
    let id = UUID()
    let name: String
    let price: Double
    let quantity: Int
}

struct ContentView: View {
    let items = [
        Item(name: "Apple", price: 120, quantity: 3),
        Item(name: "Banana", price: 80, quantity: 2),
        Item(name: "Orange", price: 60, quantity: 5)
    ]

    var totalCost: Double {
        items.reduce(0) { $0 + ($1.price * Double($1.quantity)) }
    }

    var body: some View {
        VStack {
            List(items) { item in
                Text("\(item.name): \(item.quantity) units at \(item.price) yen each")
            }

            Text("Total cost: \(totalCost, specifier: "%.2f") yen")
                .font(.title)
                .padding()
        }
        .padding()
    }
}

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

Apple: 3 units at 120 yen each
Banana: 2 units at 80 yen each
Orange: 5 units at 60 yen each
Total cost: 820.00 yen

let length = 10
let width = 5
print("The perimeter is \((length + width) * 2) and the area is \(length * width).")

let length = 10
let width = 5
let perimeter = (length + width) * 2
let area = length * width
print("The perimeter is \(perimeter) and the area is \(area).")

let strings = ["Hello", "World", "Swift", "Programming"]
var result = ""
for string in strings {
    result += string + " "
}
print(result)

let strings = ["Hello", "World", "Swift", "Programming"]
let result = strings.joined(separator: " ")
print(result)

let radius = 10.0
let circumference = 2 * 3.14159 * radius
print("The circumference is \(circumference).")

let radius = 10
let circumference = 2 * 314159 / 100000 * radius
print("The circumference is \(circumference).")

DispatchQueue.global().async {
    let result = performHeavyCalculation()
    DispatchQueue.main.async {
        print("The result is \(result)")
    }
}

var cache = [Int: Int]()
func fibonacci(_ n: Int) -> Int {
    if let result = cache[n] {
        return result
    }
    if n <= 1 {
        return n
    }
    let result = fibonacci(n - 1) + fibonacci(n - 2)
    cache[n] = result
    return result
}

let itemNames = ["Laptop", "Phone", "Tablet"]
let itemPrices = [1200, 800, 600]
let itemQuantities = [2, 5, 3]

for i in 0..<itemNames.count {
    print("\(itemNames[i]): \(itemQuantities[i]) units at \(itemPrices[i]) each, total: \(itemQuantities[i] * itemPrices[i])")
}

var totalCost = 0
for i in 0..<itemPrices.count {
    totalCost += itemPrices[i] * itemQuantities[i]
}
print("Total cost: \(totalCost)")

Laptop: 2 units at 1200 each, total: 2400
Phone: 5 units at 800 each, total: 4000
Tablet: 3 units at 600 each, total: 1800
Total cost: 8200

struct Item {
    let name: String
    let price: Int
    let quantity: Int

    var total: Int {
        return price * quantity
    }
}

let items = [
    Item(name: "Laptop", price: 1200, quantity: 2),
    Item(name: "Phone", price: 800, quantity: 5),
    Item(name: "Tablet", price: 600, quantity: 3)
]

for item in items {
    print("\(item.name): \(item.quantity) units at \(item.price) each, total: \(item.total)")
}

let totalCost = items.reduce(0) { $0 + $1.total }
print("Total cost: \(totalCost)")

Laptop: 2 units at 1200 each, total: 2400
Phone: 5 units at 800 each, total: 4000
Tablet: 3 units at 600 each, total: 1800
Total cost: 8200

for item in items {
    let message = item.total >= 5000 ? "高額商品" : "お買い得商品"
    print("\(item.name): \(item.quantity) units at \(item.price) each, total: \(item.total) (\(message))")
}

Laptop: 2 units at 1200 each, total: 2400 (お買い得商品)
Phone: 5 units at 800 each, total: 4000 (お買い得商品)
Tablet: 3 units at 600 each, total: 1800 (お買い得商品)

let optionalValue: Int? = nil
print("The value is \(optionalValue)")

if let value = optionalValue {
    print("The value is \(value)")
} else {
    print("The value is nil")
}

let price = 19.99
let quantity = 3
print("Total price is \(price * Double(quantity))")

let total = price * Double(quantity)
print("Total price is \(String(format: "%.2f", total))")

let result = 10 + 5 * 2
print("The result is \(result)")

let result = (10 + 5) * 2
print("The result is \(result)")

print("The result is \((a + b) / (c * d - e))")

let result = (a + b) / (c * d - e)
print("The result is \(result)")

let formatter = NumberFormatter()
formatter.numberStyle = .currency
let price = 1234.56
if let formattedPrice = formatter.string(from: NSNumber(value: price)) {
    print("The price is \(formattedPrice)")
}