45 lines
811 B
Go
45 lines
811 B
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// 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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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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if a := os.Args; len(a) != 2 {
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// only a is available here
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fmt.Println("Give me a number.")
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// no need to return on error
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// return
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} else if n, err := strconv.Atoi(a[1]); err != nil {
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// a, n and err are available here
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fmt.Printf("Cannot convert %q.\n", a[1])
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// no need to return on error
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// return
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} else {
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// all of the variables (names)
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// are available here
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fmt.Printf("%s * 2 is %d\n", a[1], n*2)
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}
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// a, n and err are not available here
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// they belong to the if statement
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// TRY:
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// fmt.Println(a, n, err)
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}
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