// (sometimes called _hashes_ or _dicts_ in other languages).

​

package main

​

import "fmt"

​

func main() {

​

    // To create an empty map, use the builtin `make`:

    // `make(map[key-type]val-type)`.

    m := make(map[string]int)

​

    // Set key/value pairs using typical `name[key] = val`

    // syntax.

    m["k1"] = 7

    m["k2"] = 13

​

    // Printing a map with e.g. `Println` will show all of

    // its key/value pairs.

    fmt.Println("map:", m)

​

    // Get a value for a key with `name[key]`.

    v1 := m["k1"]

    fmt.Println("v1: ", v1)

​

    // The builtin `len` returns the number of key/value

    // pairs when called on a map.

    fmt.Println("len:", len(m))

​

    // The builtin `delete` removes key/value pairs from

    // a map.

    delete(m, "k2")

    fmt.Println("map:", m)

​

    // The optional second return value when getting a

    // value from a map indicates if the key was present

    // in the map. This can be used to disambiguate

    // between missing keys and keys with zero values

    // like `0` or `""`. Here we didn't need the value

    // itself, so we ignored it with the _blank identifier_

    // `_`.

    _, prs := m["k2"]

    fmt.Println("prs:", prs)

​

    // You can also declare and initialize a new map in

    // the same line with this syntax.

    n := map[string]int{"foo": 1, "bar": 2}

    fmt.Println("map:", n)

}

​