An object that decodes instances of a data type from JSON objects.
Declaration
class JSONDecoderDiscussion
The example below shows how to decode an instance of a simple GroceryProduct type from a JSON object. The type adopts Codable so that it's decodable using a JSONDecoder instance.
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
let json = """
{
"name": "Durian",
"points": 600,
"description": "A fruit with a distinctive scent."
}
""".data(using: .utf8)!
let decoder = JSONDecoder()
let product = try decoder.decode(GroceryProduct.self, from: json)
print(product.name) // Prints "Durian"An object that encodes instances of a data type as JSON objects.
Declaration
class JSONEncoderDiscussion
The example below shows how to encode an instance of a simple GroceryProduct type from a JSON object. The type adopts Codable so that it's encodable as JSON using a JSONEncoder instance.
struct GroceryProduct: Codable {
var name: String
var points: Int
var description: String?
}
let pear = GroceryProduct(name: "Pear", points: 250, description: "A ripe pear.")
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
let data = try encoder.encode(pear)
print(String(data: data, encoding: .utf8)!)
/* Prints:
{
"name" : "Pear",
"points" : 250,
"description" : "A ripe pear."
}
*/There are three types of collections in swift
- Array
- Dictionary
- Set
Array
The array is an ordered collection type. we can access the element by the index
Dictionary
Dictionary is an unordered collection.
It’s a key-value data type. We can access the value by using the unique key.
Set
Set is also an unordered collection type. and it works on hashing
