使用Go语言实现高度可维护的跨平台应用程序

package main

import (
    "fmt"
    "os"
    "runtime"
)

func main() {
    if runtime.GOOS == "windows" {
        fmt.Println("This is a calculator application for Windows.")
    } else if runtime.GOOS == "darwin" {
        fmt.Println("This is a calculator application for macOS.")
    } else if runtime.GOOS == "linux" {
        fmt.Println("This is a calculator application for Linux.")
    } else {
        fmt.Println("This is a calculator application for an unknown operating system.")
    }

    fmt.Println("Please enter two numbers:")
    var num1, num2 float64
    fmt.Scanln(&num1, &num2)

    fmt.Println("Operation options:")
    fmt.Println("1. Add")
    fmt.Println("2. Subtract")
    fmt.Println("3. Multiply")
    fmt.Println("4. Divide")

    var option int
    fmt.Scanln(&option)

    switch option {
    case 1:
        add(num1, num2)
    case 2:
        subtract(num1, num2)
    case 3:
        multiply(num1, num2)
    case 4:
        divide(num1, num2)
    default:
        fmt.Println("Invalid option.")
    }
}

func add(num1, num2 float64) {
    fmt.Printf("Result: %.2f
", num1+num2)
}

func subtract(num1, num2 float64) {
    fmt.Printf("Result: %.2f
", num1-num2)
}

func multiply(num1, num2 float64) {
    fmt.Printf("Result: %.2f
", num1*num2)
}

func divide(num1, num2 float64) {
    if num2 == 0 {
        fmt.Println("Cannot divide by zero.")
    } else {
        fmt.Printf("Result: %.2f
", num1/num2)
    }
}