Can you explain what a Map data structure is and how it is used?

In iOS (Swift), the data structure Map typically corresponds to a Dictionary or a key-value mapping. Map is a collection that stores key-value pairs, where each unique key is associated with a specific value. This is convenient for quick search, addition, and removal of elements by key.

Example of using Dictionary in Swift:

var map: [String: Int] = [:]
map["apple"] = 3
map["banana"] = 5

if let count = map["apple"] {
    print("Number of apples: \(count)")
}

Here, "apple" and "banana" are keys, and 3 and 5 are the corresponding values. Map is used for storing and quickly accessing data by key, which is common in applications for caching, configuration, and other tasks.