Building a Simple CLI App

Build a simple command-line calculator application.

What Is a CLI App?

A command-line interface app accepts input from the terminal and displays results as text.

Getting User Input

The fmt.Scanln function can read simple input from the user.

Calculator Logic

You can combine variables, input, and switch statements to build a small calculator.

Example Code

Create or update your Go file, then run the program using go run main.go.

package main

import "fmt"

func main() {
    var a, b float64
    var op string

    fmt.Print("Enter first number: ")
    fmt.Scanln(&a)

    fmt.Print("Enter operator (+ - * /): ")
    fmt.Scanln(&op)

    fmt.Print("Enter second number: ")
    fmt.Scanln(&b)

    switch op {
    case "+":
        fmt.Println("Result:", a+b)
    case "-":
        fmt.Println("Result:", a-b)
    case "*":
        fmt.Println("Result:", a*b)
    case "/":
        if b == 0 {
            fmt.Println("Cannot divide by zero")
        } else {
            fmt.Println("Result:", a/b)
        }
    default:
        fmt.Println("Unknown operator")
    }
}

Continue Learning

After this lesson, continue to the next lesson or explore related tutorials on VisualStudioTutor.com.