Go中的排序界面

Question

Been googling and stacking around for the solution with no success.

I'm importing a JSON file to an struct, however, when I want to use it, the values come out in a random order. This is an example of my JSON file:

"Assets": {
    "asset1": "asset1.png",
    "asset2": "asset2.png"
  },
  "Colors": {
    "MainColor": [
      {
        "red": 247,
        "green": 0,
        "blue": 247
      }
    ],
    "MainGradient": [
      {
        "red": 9,
        "green": 103,
        "blue": 170
      },
      {
        "red": 18,
        "green": 138,
        "blue": 221
      }
    ]
}

I can import the JSON using Unmarshal, however, when I print it, the "red, green,blue" values outputs in random order, like this:

[{map[asset1:asset1.png asset2:asset2.png] {[map[red:247 green:0 blue:247]] [map[green:103 red:9 blue:170] map[green:138 blue:221 red:18]]}}]

As you can see, the RGB values come at random order every time. I want to know if there's a way to always output the in the same order: red, green, blue.

Thank you.

Answer 1

Maps are unordered, both in Go and per the JSON spec. You will have to call them in order as you need them.

r, g, b := color["red"], color["green"], color["blue"]

You can also unmarshal the values into a struct, which will give you a deterministic layout:

type Color struct {
    Red   int `json:"red"`
    Green int `json:"green"`
    Blue  int `json:"blue"`
}

http://play.golang.org/p/0l01NxJ4dq