Structs

Arrays, Slices and Maps deal with a single data type.

A struct is a fixed sized aggregate data type but can hold different data types.

Structs are data types so can be copied like arrays, meaning a copy of a struct is unique.

Define struct

The following example if how to define and work with a struct directly, notice the struct myPet contains a mix of strings and integer.

main.go

package main

import "fmt"

func main() {

    var myPet struct {
        name  string
        breed string
        id    int
    }

    myPet.id = 1
    myPet.name = "Mollie"
    myPet.breed = "Terrier"

    fmt.Println(myPet)
    fmt.Println(myPet.name)
}

Type struct

A more flexible approach is to define a type struct, which looks a lot like defining a class in Java, were you define a class and can have multiple objects instantiated from that "blue print".

main.go

package main

import "fmt"

func main() {

    type myPet struct {
        name  string
        breed string
        id    int
    }

    dog := myPet{
        id:    1,
        name:  "Mollie",
        breed: "Terrier",
    }

    fmt.Println(dog)

    fish := myPet{
        id:    2,
        name:  "Jelly",
        breed: "Gold",
    }

    fmt.Println(fish)
}

Compare struct

You can compare structs:

main.go

package main

import "fmt"

func main() {

    type myPet struct {
        name  string
        breed string
        id    int
    }

    dog := myPet{
        id:    1,
        name:  "Mollie",
        breed: "Terrier",
    }

    fish := myPet{
        id:    2,
        name:  "Jelly",
        breed: "Gold",
    }

    samePet := dog == fish
    fmt.Println(samePet)
}