我需要解码一个带有浮点数的JSON字符串,如下所示:
{"name":"Galaxy Nexus", "price":"3460.00"}
我使用下面的Golang代码:
package main
import (
"encoding/json"
"fmt"
)
type Product struct {
Name string
Price float64
}
func main() {
s := `{"name":"Galaxy Nexus", "price":"3460.00"}`
var pro Product
err := json.Unmarshal([]byte(s), &pro)
if err == nil {
fmt.Printf("%+v\n", pro)
} else {
fmt.Println(err)
fmt.Printf("%+v\n", pro)
}
}
当我运行它时,会得到以下结果:
json: cannot unmarshal string into Go value of type float64
{Name:Galaxy Nexus Price:0}
我想知道如何使用类型转换来解码JSON字符串。
发布于 2012-03-06 05:01:53
答案要简单得多。只需添加,告诉JSON interpeter这是一个带有,string
的字符串编码的float64 (注意,我只更改了Price
的定义):
package main
import (
"encoding/json"
"fmt"
)
type Product struct {
Name string
Price float64 `json:",string"`
}
func main() {
s := `{"name":"Galaxy Nexus", "price":"3460.00"}`
var pro Product
err := json.Unmarshal([]byte(s), &pro)
if err == nil {
fmt.Printf("%+v\n", pro)
} else {
fmt.Println(err)
fmt.Printf("%+v\n", pro)
}
}
发布于 2015-11-19 15:38:51
我只想让您知道,您可以使用json.decode
来完成此任务,而无需使用Unmarshal
。这是Go Playground
package main
import (
"encoding/json"
"fmt"
"strings"
)
type Product struct {
Name string `json:"name"`
Price float64 `json:"price,string"`
}
func main() {
s := `{"name":"Galaxy Nexus","price":"3460.00"}`
var pro Product
err := json.NewDecoder(strings.NewReader(s)).Decode(&pro)
if err != nil {
fmt.Println(err)
return
}
fmt.Println(pro)
}
发布于 2018-10-23 15:11:10
避免将字符串转换为[]byte:b := []byte(s)
。它分配一个新的内存空间,并将整个内容复制到其中。
strings.NewReader
界面更好。下面是来自godoc的代码:
package main
import (
"encoding/json"
"fmt"
"io"
"log"
"strings"
)
func main() {
const jsonStream = `
{"Name": "Ed", "Text": "Knock knock."}
{"Name": "Sam", "Text": "Who's there?"}
{"Name": "Ed", "Text": "Go fmt."}
{"Name": "Sam", "Text": "Go fmt who?"}
{"Name": "Ed", "Text": "Go fmt yourself!"}
`
type Message struct {
Name, Text string
}
dec := json.NewDecoder(strings.NewReader(jsonStream))
for {
var m Message
if err := dec.Decode(&m); err == io.EOF {
break
} else if err != nil {
log.Fatal(err)
}
fmt.Printf("%s: %s\n", m.Name, m.Text)
}
}
https://stackoverflow.com/questions/9452897
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