Files
learngo/x-tba/maps/04-internals-cloning/main.go
2019-02-26 14:06:02 +03:00

78 lines
1.6 KiB
Go

// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
import (
"fmt"
"os"
)
func main() {
args := os.Args[1:]
if len(args) != 1 {
fmt.Println("[english word] -> [turkish word]")
return
}
query := args[0]
dict := map[string]string{
"good": "iyi",
"great": "harika",
"perfect": "mükemmel",
// #5: this overwrites the mükemmel in the turkish map
"awesome": "mükemmel",
}
// #1: map value is a pointer to a real map in the memory
// turkish := dict
// turkish["good"] = "güzel"
// dict["great"] = "kusursuz"
// #6: delete can delete a pair from a map
delete(dict, "awesome")
// #7: no-op
delete(dict, "awesome")
delete(dict, "notexisting")
// #8: destroying a map completely (false)
// dict = nil
// #9: destroying a map completely (true)
// replaces the whole loop with a single instruction:
// "call runtime.mapclear()"
for k := range dict {
delete(dict, k)
}
// #2: make initializes a new map value and returns a pointer to it
// turkish := make(map[string]string)
// #3: make(T, hint) => hint is an advice for initing a large enough map
turkish := make(map[string]string, len(dict))
for k, v := range dict {
turkish[v] = k
}
// #4: add turkish dictionary
// fmt.Printf("english: %q\nturkish: %q\n", dict, turkish)
if value, ok := dict[query]; ok {
fmt.Printf("%q means %#v\n", query, value)
return
}
if value, ok := turkish[query]; ok {
fmt.Printf("%q means %#v\n", query, value)
return
}
fmt.Printf("%q not found.\n", query)
}