How do you work with maps in Go?

You create a map with make or a map literal, then read and write entries with m[key]. A map is Go's built-in hash table of key-value pairs. Reading a missing key returns the zero value. The comma-ok form v, ok := m[key] tells a missing key from a stored zero. delete removes a key, and len counts the entries.

• Keys must be comparable types, such as strings, numbers or structs of them.
• Iteration order is not specified, so never rely on it.
• A nil map can be read but panics on write, so always create the map first.
• Maps are not safe for concurrent writes, so guard a shared map with a sync.Mutex.

// Creating maps
ages := make(map[string]int)
ages["Alice"] = 30
ages["Bob"] = 25

// Map literal
ages = map[string]int{
    "Alice": 30,
    "Bob":   25,
}

// Checking if key exists
age, exists := ages["Alice"]
if exists {
    fmt.Println("Alice's age:", age)
}

// Deleting keys
delete(ages, "Bob")