summaryrefslogtreecommitdiffstats
path: root/src/encoding/json/example_marshaling_test.go
diff options
context:
space:
mode:
Diffstat (limited to 'src/encoding/json/example_marshaling_test.go')
-rw-r--r--src/encoding/json/example_marshaling_test.go73
1 files changed, 73 insertions, 0 deletions
diff --git a/src/encoding/json/example_marshaling_test.go b/src/encoding/json/example_marshaling_test.go
new file mode 100644
index 0000000..7f15c74
--- /dev/null
+++ b/src/encoding/json/example_marshaling_test.go
@@ -0,0 +1,73 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package json_test
+
+import (
+ "encoding/json"
+ "fmt"
+ "log"
+ "strings"
+)
+
+type Animal int
+
+const (
+ Unknown Animal = iota
+ Gopher
+ Zebra
+)
+
+func (a *Animal) UnmarshalJSON(b []byte) error {
+ var s string
+ if err := json.Unmarshal(b, &s); err != nil {
+ return err
+ }
+ switch strings.ToLower(s) {
+ default:
+ *a = Unknown
+ case "gopher":
+ *a = Gopher
+ case "zebra":
+ *a = Zebra
+ }
+
+ return nil
+}
+
+func (a Animal) MarshalJSON() ([]byte, error) {
+ var s string
+ switch a {
+ default:
+ s = "unknown"
+ case Gopher:
+ s = "gopher"
+ case Zebra:
+ s = "zebra"
+ }
+
+ return json.Marshal(s)
+}
+
+func Example_customMarshalJSON() {
+ blob := `["gopher","armadillo","zebra","unknown","gopher","bee","gopher","zebra"]`
+ var zoo []Animal
+ if err := json.Unmarshal([]byte(blob), &zoo); err != nil {
+ log.Fatal(err)
+ }
+
+ census := make(map[Animal]int)
+ for _, animal := range zoo {
+ census[animal] += 1
+ }
+
+ fmt.Printf("Zoo Census:\n* Gophers: %d\n* Zebras: %d\n* Unknown: %d\n",
+ census[Gopher], census[Zebra], census[Unknown])
+
+ // Output:
+ // Zoo Census:
+ // * Gophers: 3
+ // * Zebras: 2
+ // * Unknown: 3
+}