57 lines
987 B
Go
57 lines
987 B
Go
// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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// For more tutorials : https://learngoprogramming.com
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// In-person training : https://www.linkedin.com/in/inancgumus/
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// Follow me on twitter: https://twitter.com/inancgumus
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package main
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import (
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"fmt"
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"os"
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"strconv"
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)
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func main() {
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// lesson: switch
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if len(os.Args) != 4 {
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fmt.Println("Usage: calc <number1> <operator> <number2>")
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return
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}
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a, err := strconv.ParseFloat(os.Args[1], 64)
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if err != nil {
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fmt.Println("Please provide a valid number")
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return
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}
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b, err := strconv.ParseFloat(os.Args[3], 64)
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if err != nil {
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fmt.Println("Please provide a valid number")
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return
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}
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// multiple declare
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var (
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// declare & assign
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op = os.Args[2]
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res float64
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)
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switch op {
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case "+":
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res = a + b
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case "-":
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res = a - b
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case "*":
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res = a * b
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case "/":
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res = a / b
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}
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fmt.Printf("%v %v %v = %v\n", a, op, b, res)
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}
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