Simple use of dictionaries in Swift 5.

Dictionaries.swift

//
// Simple use of dictionaries
//

// basic dictionary
var age = [
    "Jack": 23,
    "Alice": 25
]
age["Mark"] = 45
print(age["Mark"]!)     // 45
print(age)     // ["Mark": 45, "Alice": 25, "Jack": 23]

age.removeValue(forKey: "Jack")
print(age)     // ["Alice": 25, "Mark": 45]


// default values
var user = [
    "Jack": "Sparrow",
    "Will": "Turner"
]
print(user["Hector", default: "Barbossa"])     // Barbossa


// empty collection
var weight = [String: Double]()
weight["Richard"] = 150

print(weight)     // ["Richard": 150.0]
print(weight["Richard"]!)     // 150.0