maps.nf.id.au.go

package main

import "fmt"

func main() {

        m := make(map[string]int) //initialize
        //map[keyType]valueType

        m["Alice"] = 21 //Store Values to initialized
        //array.
        //  m["keyType"] = valueType 
        //  "Alice" is the key
        //  21 is the value
        m["Bob"] = 17

        a := m["Alice"]
        b := m["Bob"]

        for k, v := range m {
                fmt.Println(k, v)
        }
        fmt.Println("the value mapped to key Alice:", a)
        fmt.Println("the value mapped to key Bob:", b)

        c := m["Charlie"] //retrieving a value from a key that's not in the map c == 0
        fmt.Println("c", c)
        // map returns two values - the key's value and bool testing key's presence.
        d, okd := m["Alice"]   // d == 21, okd == true
        e, oke := m["Charlie"] // e == 0, oke == false
        fmt.Println("d, okd:",d, okd)
        fmt.Println("e, oke:",e, oke)
        // To remove a key/value entry from a map, flip it around and assign false as the second value:
        m["Bob"] = 0, false // the value 0 could have been any int, it's the false that's important
        f, okf := m["Bob"]  //check the 2nd return-is "Bob" a valid key?
        // b==0, okb == false
        fmt.Println("f, okf:", f, okf)
}