How can you effectively update or retrieve values in a counter structure?

In Go, to efficiently update or retrieve the value of a counter in a map, the following approach is usually used:

counters := make(map[string]int)

// Increment the counter for a key
key := "example"
counters[key]++ // if the key does not exist, the default value is 0, then it is incremented by 1

// Retrieve the value with a check for the key's existence
value, ok := counters[key]
if ok {
    // key exists, value contains the value
} else {
    // key does not exist, value == 0
}

This method allows safe working with maps without the need to initialize keys beforehand.