Sorting structs in GoLang

colors-by-area.go

package main

import "fmt"
import "sort"

type Color struct {
	Area float64
}

type ByArea []Color

func (c ByArea) Len() int           { return len(c) }
func (c ByArea) Swap(i, j int)      { c[i], c[j] = c[j], c[i] }
func (c ByArea) Less(i, j int) bool { return c[i].Area > c[j].Area }

func main() {
	var colors = []Color{
		{1.0},
		{0.5},
		{0.9},
		{0.1},
	}
	//  before sort
	fmt.Println(colors)

	sort.Sort(ByArea(colors))

  	//  after sort
	fmt.Println(colors)
}