Maps in Golang

maps.go

package main

import "fmt"

// Map

func main() {
  // statically type [key]values{}
  colors := map[string]string{
    "red": "#ff0000",
    "green": "#7845AF",
  }
  // printing colors
  fmt.Println(colors)

  // another way of declaring
  // var colores map[string]string // init empty by default

  // another way (builtin function)
  colores2 := make(map[string]string)

  // adding values - always use brackers
  colores2["white"] = "#ffffff"

  // delete (element, key)
  delete(colores2, "white")

  // printing
  printMap(colors)

}

// iterating map
func printMap(c map[string]string) {
  for color, hex := range c {
    fmt.Println("Hex code for", color, "is", hex)
  }
}

maps.md

Maps in Golang

This is a very similar data type as structs, but it has certain differences.

The keys and values of the map are statically typed (All the same type!)

Here's a definition: m map[string] string where the m is the argument name and the [string] is the type of the map.

Characteristics of the Maps

1. All keys must be the same type
2. All values must be the same type
3. Keys are indexed, we can add an iterator over them
4. Is used to represent a collection of related properties
5. Doesn't need to know all the keys at compile time
6. Most important: is a reference data type

And compared to Structs, we have:

1. Values can be of different types in terms of keys and values
2. Keys does not support indexing
3. You need to know all the different fields at compile time.
4. Is used to represent a "thing" with a lot of different properties.