1. Functions allow defining reusable chunks of code that can optionally take parameters and return values. Functions can have default parameter values. 2. Classes define blueprints for objects that can contain properties like name and age, as well as methods like walk(). Classes can inherit from other classes and conform to protocols. 3. Protocols define a blueprint of functionality that classes and structures can conform to, like requiring a coding() method.

1. Function, Class
By Akira Hirakawa

2. Topics
• function
• class

3. Function
// Chunks of Code
func sayHello() {
print("hello")
}

4. Function with parameters
func sayHello(name: String) {
let greeting = "Hello, " + name + "!"
print(greeting)
}
sayHello("Akira")

5. Function with Multiple
Parameters
func sayHello(name: String, from: String) {
let greeting = "Hello, I'm (name), from (from)"
print(greeting)
}
sayHello("Akira", from: "Japan")

6. Function with return value
func sayHello(name: String) -> String {
let greeting = "Hello, " + name + "!"
return greeting
}
print(sayHello("Akira"))

7. Function Parameter Names
func sayHello(name: String, from: String) {
let greeting = "Hello, I'm (name), from (from)"
print(greeting)
}
sayHello("Akira", from: “Japan")
• the first parameter omits external name
• second and subsequent parameters users local name as
external name

8. Specifying External
Parameter Names
func sayHello(name localName: String, from: String) {
let greeting = "Hello, I'm (localName), from (from)"
print(greeting)
}
sayHello(name:"Akira", from: “Japan")
• write external param name before local param

9. Omitting External Param Name
func sayHello(name: String, _ from: String) {
let greeting = "Hello, I'm (name), from (from)"
print(greeting)
}
sayHello("Akira", "Japan")
• write underscore before local name

10. Default Parameter
func hello(name: String = "anonymous") {
let greeting = "Hello, " + name + "!"
print(greeting)
}
hello()
hello("Singapore")

11. Class
class SomeClass {
}
blueprint of an object that contains
information , behaviour

12. Class can
• Define properties
• Define methods

13. Properties, Methods
class Person {
var name: String
var age: Int
// initialize
init(name aName: String, age aAge: Int) {
name = aName
age = aAge
}
// instance method
func walk() {
}
// class method
class func hello() {
}
}
Person(name: "Akira", age: 100).walk()
Person.hello()

14. Inheritance
class SomeClass {
}
class SomeClass2: SomeClass {
}

15. Protocol
• to define a blueprint of methods, properties etc
protocol GeekProtocol {
func coding() -> Bool
}
class SGGeek: GeekProtocol {
func coding() -> Bool {
print("coding coding coding")
return true
}
}

16. thanks