github.com/huandu/go@v0.0.0-20151114150818-04e615e41150/doc/progs/json3.go (about)

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"encoding/json"
     9  	"fmt"
    10  	"log"
    11  	"reflect"
    12  )
    13  
    14  func Decode() {
    15  	b := []byte(`{"Name":"Wednesday","Age":6,"Parents":["Gomez","Morticia"]}`)
    16  
    17  	var f interface{}
    18  	err := json.Unmarshal(b, &f)
    19  
    20  	// STOP OMIT
    21  
    22  	if err != nil {
    23  		panic(err)
    24  	}
    25  
    26  	expected := map[string]interface{}{
    27  		"Name": "Wednesday",
    28  		"Age":  float64(6),
    29  		"Parents": []interface{}{
    30  			"Gomez",
    31  			"Morticia",
    32  		},
    33  	}
    34  
    35  	if !reflect.DeepEqual(f, expected) {
    36  		log.Panicf("Error unmarshalling %q, expected %q, got %q", b, expected, f)
    37  	}
    38  
    39  	f = map[string]interface{}{
    40  		"Name": "Wednesday",
    41  		"Age":  6,
    42  		"Parents": []interface{}{
    43  			"Gomez",
    44  			"Morticia",
    45  		},
    46  	}
    47  
    48  	// STOP OMIT
    49  
    50  	m := f.(map[string]interface{})
    51  
    52  	for k, v := range m {
    53  		switch vv := v.(type) {
    54  		case string:
    55  			fmt.Println(k, "is string", vv)
    56  		case int:
    57  			fmt.Println(k, "is int", vv)
    58  		case []interface{}:
    59  			fmt.Println(k, "is an array:")
    60  			for i, u := range vv {
    61  				fmt.Println(i, u)
    62  			}
    63  		default:
    64  			fmt.Println(k, "is of a type I don't know how to handle")
    65  		}
    66  	}
    67  
    68  	// STOP OMIT
    69  }
    70  
    71  func main() {
    72  	Decode()
    73  }