• Classes

    A class in programming is like a group of people. For example, if you have a group of friends, each person in the group is called a "friend". In programming, we call each person in the group a "class". Just like your friends might all have different names and personalities, classes can also have different names and qualities. So when you write code, you can create different classes with different names and abilities to do things.

      • Object Classes

      • Go

        Example of object class in go.
        package main

import "fmt"

type Person struct {
	name string
	age  int
}

func (p Person) greet() {
	fmt.Println("Hello my name is " + p.name)
}

func main() {
	var human = Person{"John", 36}

	fmt.Println(human.name) // John
	fmt.Println(human.age)  // 36
	human.greet()		   // Hello my name is John
}

      • Trait Classes

      • Go

        Example of trait class in go.
        package main

import "fmt"

type HasFlippers string

type HasFeathers string

func (h HasFlippers) swim() string {
	return "can swim"
}

func (h HasFeathers) fly() string {
	return "can fly"
}

type Duck struct {
	HasFlippers
	HasFeathers
}

type Seal struct {
	HasFlippers
}

func main() {
	var a Duck
	fmt.Println(a.swim())
	fmt.Println(a.fly())

	var b Seal
	fmt.Println(b.swim())
}

      • Interface Classes

      • Go

        Example of interface class in go.
        package main

import (
	"fmt"
	"math"
)

type Shape interface {
	Area() float64
}

type Rectangle struct {
	width  float64
	height float64
}

type Circle struct {
	radius float64
}

func (r Rectangle) Area() float64 {
	return r.width * r.height
}

func (c Circle) Area() float64 {
	return math.Pi * c.radius * c.radius
}

func main() {
	var a, b Shape
	
	a = Rectangle{width: 3, height: 5}
	b = Circle{radius: 4}

	fmt.Printf("area of a is %f", a.Area()) // area of a is 15.000000
	fmt.Printf("area of b is %f", b.Area()) // area of b is 50.265482
}

      • Struct Classes

      • Go

        Example of struct class in go.
        package main

import "fmt"

type Person struct {
	name string
	age  int
}

func main() {
	var human = Person{"John", 36}

	fmt.Println(human.name) // John
	fmt.Println(human.age)  // 36
}

      • Enum Classes

      • Go

        Example of enum class in go.
        package main

import "fmt"

const (
	Sunday	int = 0
	Monday	int = 1
	Tuesday   int = 2
	Wednesday int = 3
	Thursday  int = 4
	Friday	int = 5
	Saturday  int = 6
)

func main() {
	var day int = 4

	if day == Saturday || day == Sunday {
		fmt.Println("a weekend")
	} else {
		fmt.Println("a weekday") // a weekday
	}
}