<17> go json

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go裡的encoding/json 包專門處理json

import (    "encoding/json"    "fmt"    "os")type Response1 struct {    Page   int    Fruits []string}type Response2 struct {    Page   int      `json:"page"`    Fruits []string `json:"fruits"`}func main() {    fmt.Println("Start Main func()")    // 單個常見類型的處理    bolB, _ := json.Marshal(true)    fmt.Println(string(bolB))    intB, _ := json.Marshal(1)    fmt.Println(string(intB))    fltB, _ := json.Marshal(2.34)    fmt.Println(string(fltB))    strB, _ := json.Marshal("gopher")    fmt.Println(string(strB))    slcD := []string{"apple", "peach", "pear"}    slcB, _ := json.Marshal(slcD)    fmt.Println(string(slcB))    mapD := map[string]int{"apple": 5, "lettuce": 7}    mapB, _ := json.Marshal(mapD)    fmt.Println(string(mapB))    // struct的處理    res1D := &Response1{        Page:   1,        Fruits: []string{"apple", "peach", "pear"}}    res1B, _ := json.Marshal(res1D)    fmt.Println(string(res1B))    res2D := &Response2{        Page:   1,        Fruits: []string{"apple", "peach", "pear"}}    res2B, _ := json.Marshal(res2D)    fmt.Println(string(res2B))    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)    fmt.Println(dat["num"])    num := dat["num"].(float64)    fmt.Println(num)    strs := dat["strs"].([]interface{})    str1 := strs[0].(string)    fmt.Println(str1)    // json => struct    str := `{"page": 1, "fruits": ["apple", "peach"]}`    res := Response2{}    json.Unmarshal([]byte(str), &res)    fmt.Println(res)    fmt.Println(res.Fruits[0])    enc := json.NewEncoder(os.Stdout)    d := map[string]int{"apple": 5, "lettuce": 7}    enc.Encode(d)    ares2D := &Response2{        Page:   1,        Fruits: []string{"apple", "peach", "pear"}}    ares2B, _ := json.MarshalIndent(ares2D, "a", "b")    fmt.Println(string(ares2B))}