Solution: Swift programming revision for Level 2

Sample answer (Swift)

This is one complete working solution that matches the requirements in the revision task. It uses functions, a loop, and selection to process the room and furniture data.

Full program

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func readNumber(prompt: String) -> Double {
    print(prompt)
    var returnValue = -1.0
    guard let userInput = readLine(), let number = Double(userInput), number > 0 else {
        print("Invalid number.")
        return readNumber(prompt: prompt)
    }
    returnValue = number
    return returnValue
}

@main
struct SwiftPlayground {
    static func main() {
        let maximumItemVolume = 2.0

        let roomLength = readNumber(prompt: "Enter the room length: ")
        let roomWidth = readNumber(prompt: "Enter the room width: ")
        let roomHeight = readNumber(prompt: "Enter the room height: ")

        let roomArea = roomLength * roomWidth
        let roomVolume = roomArea * roomHeight

        print("Room area: \(roomArea) m²")
        print("Room volume: \(roomVolume) m³")

        let furnitureVolumes = [1.2, 0.8, 2.5, 0.6, 1.0]

        var totalFurnitureVolume = 0.0

        furnitureVolumes.enumerated().forEach { index, volume in
            print("Item \(index + 1): \(volume) m³")
            if volume > maximumItemVolume {
                print("Oversized item detected.")
            }
            totalFurnitureVolume = totalFurnitureVolume + volume
        }

        let usableVolume = roomVolume - totalFurnitureVolume
        print("Usable volume: \(usableVolume) m³")

    }
}

Breakdown: Input function

func readNumber(prompt: String) -> Double {
    print(prompt)
    var returnValue = -1.0
    guard let userInput = readLine(), let number = Double(userInput), number > 0 else {
        print("Invalid number.")
        return readNumber(prompt: prompt)
    }
    returnValue = number
    return returnValue
}

The function prints a prompt, reads a line, converts it to a Double, and checks it is positive. If the input is invalid, it calls itself again to keep asking until a valid value is entered.

Breakdown: Room calculations

let roomLength = readNumber(prompt: "Enter the room length: ")
let roomWidth = readNumber(prompt: "Enter the room width: ")
let roomHeight = readNumber(prompt: "Enter the room height: ")

let roomArea = roomLength * roomWidth
let roomVolume = roomArea * roomHeight

print("Room area: \(roomArea) m²")
print("Room volume: \(roomVolume) m³")

The room dimensions are read using the helper function, then area and volume are calculated. The values are printed immediately so the user can see the computed results.

Breakdown: Furniture loop + oversized check

let furnitureVolumes = [1.2, 0.8, 2.5, 0.6, 1.0]
var totalFurnitureVolume = 0.0

furnitureVolumes.enumerated().forEach { index, volume in
    print("Item \(index + 1): \(volume) m³")
    if volume > maximumItemVolume {
        print("Oversized item detected.")
    }
    totalFurnitureVolume = totalFurnitureVolume + volume
}

enumerated() provides an index for numbering each item. The if statement flags any item larger than the allowed maximum volume.

Breakdown: Usable volume

let usableVolume = roomVolume - totalFurnitureVolume
print("Usable volume: \(usableVolume) m³")

The usable space is calculated by subtracting the total furniture volume from the room volume. This final value is printed as the result of the program.