add: struct encoding/decoding

24-structs/06-encoding/main.go

@@ -0,0 +1,42 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+type permissions map[string]bool // #3
+
+type user struct { // #1
+	Name        string      `json:"username"`
+	Password    string      `json:"-"`
+	Permissions permissions `json:"perms,omitempty"` // #6
+
+	// name        string // #1
+	// password    string // #1
+	// permissions // #3
+}
+
+func main() {
+	users := []user{ // #2
+		{"inanc", "1234", nil},
+		{"god", "42", permissions{"admin": true}},
+		{"devil", "66", permissions{"write": true}},
+	}
+
+	// out, err := json.Marshal(users) // #4
+	out, err := json.MarshalIndent(users, "", "\t") // #5
+	if err != nil {                                 // #4
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(string(out)) // #4
+}

24-structs/07-decoding/main.go

@@ -0,0 +1,47 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+type user struct {
+	Name        string          `json:"username"`
+	Permissions map[string]bool `json:"perms"`
+}
+
+func main() {
+	var input []byte
+	for in := bufio.NewScanner(os.Stdin); in.Scan(); {
+		input = append(input, in.Bytes()...)
+	}
+
+	var users []user
+	if err := json.Unmarshal(input, &users); err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	for _, user := range users {
+		fmt.Print("+ ", user.Name)
+
+		switch p := user.Permissions; {
+		case p == nil:
+			fmt.Print(" has no power.")
+		case p["admin"]:
+			fmt.Print(" is an admin.")
+		case p["write"]:
+			fmt.Print(" can write.")
+		}
+		fmt.Println()
+	}
+}

24-structs/07-decoding/users.json

@@ -0,0 +1,17 @@
+[
+	{
+		"username": "inanc"
+	},
+	{
+		"username": "god",
+		"perms": {
+			"admin": true
+		}
+	},
+	{
+		"username": "devil",
+		"perms": {
+			"write": true
+		}
+	}
+]