How to Use a Map as a Set in Go

Use a map[KeyType]bool where the key is your unique value and the boolean is always true to simulate a set. Check for existence with the comma-ok idiom to distinguish between missing keys and zero values.

mySet := make(map[string]bool)

// Add an item
mySet["apple"] = true

// Check if an item exists
if exists, ok := mySet["apple"]; ok {
    // "apple" is in the set
}

// Remove an item
delete(mySet, "apple")

Go doesn't have a built-in set type, so developers use a map to store unique items. You treat the map keys as the items in your set and ignore the values, which are just placeholders. It's like using a list of names on a whiteboard to track who is in a meeting; the name is what matters, not the marker color used to write it.