JSON encoding in Go

Struct tags map Go fields to JSON keys.

type Repo struct {
    Name  string `json:"name"`
    Stars int    `json:"stargazers_count"`
    Fork  bool   `json:"fork,omitempty"`
}

func encode(repos []Repo) ([]byte, error) {
    return json.MarshalIndent(repos, "", "  ")
}

func decode(data []byte) ([]Repo, error) {
    var repos []Repo
    err := json.Unmarshal(data, &repos)
    return repos, err
}

How it works

1. Backtick tags rename fields for JSON.
2. omitempty drops zero values from output.
3. Marshal and Unmarshal convert both ways.

Keywords and builtins used here

• bool
• byte
• error
• func
• int
• return
• string
• struct
• type
• var

The run, in numbers

Lines

15

Characters to type

330

Tokens

79

Three-star pace

100 tpm

At the three-star pace of 100 tokens a minute, this run takes about 47 seconds.

Type this snippet

Step 1 of 3 in Encoding, step 1 of 26 in Standard library & project layout.

Next →