104 lines
1.8 KiB
Go
104 lines
1.8 KiB
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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"strconv"
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)
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func main() {
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local := 10
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show(local)
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incrWrong(local)
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fmt.Printf("local → %d\n", local)
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// incr(local)
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local = incr(local)
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show(local)
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local = incrBy(local, 5)
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show(local)
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_, err := incrByStr(local, "TWO")
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if err != nil {
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fmt.Printf("err → %s\n", err)
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}
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local, _ = incrByStr(local, "2")
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show(local)
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// CHAINING
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// can't save the number back into main's local
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show(incrBy(local, 2))
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show(local)
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// can't pass the results of the multiple-value returning func
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// show(incrByStr(local, "3"))
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// can call showErr directly because it accepts the same types
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// of parameters as with incrByStr's result values.
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// local = sanitize(incrByStr(local, "NOPE"))
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// show(local)
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local = sanitize(incrByStr(local, "2"))
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show(local)
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local = limit(incrBy(local, 5), 2000)
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show(local)
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}
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func show(n int) {
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// can't access main's local
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// fmt.Printf("show : n = %d\n", local)
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fmt.Printf("show → n = %d\n", n)
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}
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// wrong: incr can't access to main's `local`
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func incrWrong(n int) {
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// n := local
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n++
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// can't return (there are no result values)
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// return n
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}
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func incr(n int) int {
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n++
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return n
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}
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func incrBy(n, factor int) int {
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return n * factor
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}
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func incrByStr(n int, factor string) (int, error) {
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m, err := strconv.Atoi(factor)
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n = incrBy(n, m)
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return n, err
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}
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func sanitize(n int, err error) int {
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if err != nil {
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return 0
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}
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return n
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}
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func limit(n, lim int) (m int) {
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// var m int
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m = n
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if m >= lim {
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m = lim
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}
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// return m
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return
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}
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