50 lines
791 B
Go
50 lines
791 B
Go
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 default + multiple case
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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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var (
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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 "+", "plus":
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op, res = "+", a+b
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case "-", "minus":
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op, res = "-", a-b
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case "*", "times":
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op, res = "*", a*b
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case "/", "div":
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op, res = "/", a/b
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default:
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fmt.Println("Please provide a valid operation.")
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return
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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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