Maps are Go’s built-in associative data type (sometimes called hashes or dicts in other languages)
To create an empty map, use the builtin make:
make(map[key-type]val-type)
Set key/value pairs using typical name[key]=val syntax
Printing a map with e.g. fmt.Println will show all of its key/value pairs
Get a value for a key with name[key]
If the key doesn't exist, the zero valuue of the value type is returned
The builtin len returns the number of key/value pairs when called on a map
The builtin delete removes key/value pairs from a map
To remove all key/value pairs from a map, use the clear builtin
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 _
You can also declare and initialize a new map in the same line with this syntax
The maps package contains a number of useful utility functions for maps
Note that maps appear in the form map[k:v k:v] when printed with fmt.Println