Go Mark 2

collections of fields

1type person struct {
2  first string
3  last string
4}
go
1humanPersona := person{
2  first: "James",
3  last: "Bond",
4}
5
6lName := humanPerson.last
go

Structs can be nested

 1type car struct {
 2  brand string
 3  model string
 4  doors int
 5  frontWheel wheel
 6  readWheel wheel
 7}
 8type wheel struct {
 9  radius int
10  material string
11}
12myCar := car{}
13myCar.frontWheel.radius = 5
...
go

Fake (data-only) inheritence

 1type car struct {
 2  brand string
 3  model string
 4}
 5
 6type truck struct {
 7  car
 8  bedSize int
 9}
10
11// embedded struct fields are accessed at top lvl
12redTruck := truck {
13  bedSize: 10,
14  car: car{
15    brand: "dodge",
16    model: "ram",
17  },
18}
19redTruck.brand
20redTruck.bedSize
...
go

structs can have methods. methods are funcs that have a receiver

 1type rect struct {
 2  width int
 3  height int
 4}
 5
 6func (r rect) area() int {
 7  return r.width * r.height
 8}
 9
10var r = rect {
11  width: 5,
12  height: 10,
13}
14r.area()
...
go

A set of method signatures. A type "implements" an interface just by having those methods

 1type shape interface {
 2  area() float64
 3}
 4
 5type rect struct{
 6  width, height float64
 7}
 8
 9func (r rect)area() float64 {
10  return r.width * r.height
11}
12
13func printShape(s shape) {
14  fmt.Printf("Area: %v", s.area())
15}
...
go