003_golang的json解析

package main

import (
	"os"
	"encoding/json"
	"fmt"
)

type response1 struct {
	Page   int
	Fruits []string
}
type response2 struct {
	Page   int      `json:"page"`
	Fruits []string `json:"fruits"`
}
func main() {
	bolB, _ := json.Marshal(true)
	fmt.Println(string(bolB))  //true

	intB, _ := json.Marshal(1)
	fmt.Println(string(intB))  //1

	fltB, _ := json.Marshal(2.34)
	fmt.Println(string(fltB))  //2.34

	strB, _ := json.Marshal("gopher")
	fmt.Println(string(strB))  //"gopher"

	slcD := []string{"apple", "peach", "pear"}
	slcB, _ := json.Marshal(slcD)
	fmt.Println(string(slcB))	//["apple","peach","pear"]

	mapD := map[string]int{"apple": 5, "lettuce": 7}
	mapB, _ := json.Marshal(mapD)
	fmt.Println(string(mapB))	//{"apple":5,"lettuce":7}

	fmt.Println(new(response1))	//&{0 []}
	res1D := &response1{
		Page:   1,
		Fruits: []string{"apple", "peach", "pear"}}
	res1B, _ := json.Marshal(res1D)
	fmt.Println(string(res1B))	//{"Page":1,"Fruits":["apple","peach","pear"]}

	res2D := &response2{
		Page:   1,
		Fruits: []string{"apple", "peach", "pear"}}
	res2B, _ := json.Marshal(res2D)
	fmt.Println(string(res2B))	//{"page":1,"fruits":["apple","peach","pear"]}

	byt := []byte(`{"num":6.13,"strs":["a","b"]}`)

	var dat map[string]interface{}

	if err := json.Unmarshal(byt, &dat); err != nil {
		panic(err)
	}
	fmt.Println(dat)	//map[strs:[a b] num:6.13]

	num := dat["num"].(float64)
	fmt.Println(num)	//6.13

	strs := dat["strs"].([]interface{})
	str1 := strs[0].(string)
	fmt.Println(str1)	//a

	str := `{"page": 1, "fruits": ["apple", "peach"]}`
	res := response2{}
	json.Unmarshal([]byte(str), &res)
	fmt.Println(res)			//{1 [apple peach]}
	fmt.Println(res.Fruits[0])	//apple

	enc := json.NewEncoder(os.Stdout)
	d := map[string]int{"apple": 5, "lettuce": 7}
	enc.Encode(d)				//{"apple":5,"lettuce":7}
}