如何在Go中的字节片中使用变量

Question

Probably a big noob question here, so please bear with me.

To send an HTTP POST request in Go with some body, I can do this:

var jsonStr = []byte(`{"someVar":"someValue"}`)
req, err := http.NewRequest("POST", APIURL, bytes.NewBuffer(jsonStr))

However, it seems that I can't use a variable instead of "someValue", like this:

someValue := "SomeValue"
var jsonStr = []byte(`{"someVar":someValue}`)

Can someone point me in the right direction?

Answer 1

That is because it is a string literal. I suggest trying to serialize your type using encoding/json .

type MyPostBody struct {
    SomeVar string `json:"someVar"`
}

pb := &MyPostBody{SomeVar: "someValue"}
jsonStr, err := json.Marshal(pb)
if err != nil {
    log.Fatalf("could not marshal JSON: %s", err)
}

req, err := http.NewRequest("POST", APIURL, bytes.NewBuffer(jsonStr))

Answer 2

or format the string

someValue := "SomeValue"
var jsonStr = []byte(fmt.Sprintf(`{"someVar":"%v"}`, someValue))