一个简单的问题:如何使用json包解析Go中的字符串(这是一个数组)?
type JsonType struct{
Array []string
}
func main(){
dataJson = `["1","2","3"]`
arr := JsonType{}
unmarshaled := json.Unmarshal([]byte(dataJson), &arr.Array)
log.Printf("Unmarshaled: %v", unmarshaled)
}
The return value of Unmarshal
is an err, and this is what you are printing out:
// Return value type of Unmarshal is error.
err := json.Unmarshal([]byte(dataJson), &arr)
You can get rid of the JsonType
as well and just use a slice:
package main
import (
"encoding/json"
"log"
)
func main() {
dataJson := `["1","2","3"]`
var arr []string
_ = json.Unmarshal([]byte(dataJson), &arr)
log.Printf("Unmarshaled: %v", arr)
}
// prints out:
// 2009/11/10 23:00:00 Unmarshaled: [1 2 3]
Code on play: https://play.golang.org/p/GNWlylavam
Note: This answer was written before the question was edited. In the original question &arr
was passed to json.Unmarshal()
:
unmarshaled := json.Unmarshal([]byte(dataJson), &arr)
You pass the address of arr
to json.Unmarshal()
to unmarshal a JSON array, but arr
is not an array (or slice), it is a struct value.
Arrays can be unmarshaled into Go arrays or slices. So pass arr.Array
:
dataJson := `["1","2","3"]`
arr := JsonType{}
err := json.Unmarshal([]byte(dataJson), &arr.Array)
log.Printf("Unmarshaled: %v, error: %v", arr.Array, err)
Output (try it on the Go Playground):
2009/11/10 23:00:00 Unmarshaled: [1 2 3], error: <nil>
Of course you don't even need the JsonType
wrapper, just use a simple []string
slice:
dataJson := `["1","2","3"]`
var s []string
err := json.Unmarshal([]byte(dataJson), &s)