Map

A map is a hash table or dictionary that stores key and value pairs. The key and value can be any data types, including maps themselves, creating multiple dimensions.

The order is not guaranteed. You can iterate over a map multiple times and it might be different. Additionally, maps are not concurrent safe. If you must share a map between threads, use a mutex.

Here are some example map usages:

package main

import (
   "fmt"
   "reflect"
)

func main() {
   // Nil maps will cause runtime panic if used 
   // without being initialized with make()
   var intToStringMap map[int]string
   var stringToIntMap map[string]int
   fmt.Println(reflect.TypeOf(intToStringMap))
   fmt.Println(reflect.TypeOf(stringToIntMap))

   // Initialize a map using make
   map1 := make(map[string]string)
   map1["Key Example"] = "Value Example"
   map1["Red"] = "FF0000"
   fmt.Println(map1)

   // Initialize a map with literal values
   map2 := map[int]bool{
      4:  false,
      6:  false,
      42: true,
   }

   // Access individual elements using the key
   fmt.Println(map1["Red"])
   fmt.Println(map2[42])

   // Use range to iterate through maps
   for key, value := range map2 {
      fmt.Printf("%d: %t\n", key, value)
   }

}