Golang transform http.Header into array

I'm sending POST request:

req, err := http.NewRequest("POST", link, bytes.NewBuffer(jsonStr))
client := &http.Client{Timeout: tm}
resp, err := client.Do(req)

I receive resp.Header in format with type http.Header

I need to something like this:

[
    "Server: nginx/1.4.4",
    "Date: Wed, 24 Feb 2016 19:09:49 GMT"
]

I don't know how to approach this problem, because I don't know how to deal with http.Header datatype. Could someone help please

resp.Header is of type http.Header. You can see in the documentation that this type is also a map, so you can access it in two different ways:

1. By using http.Header's methods:

   serverValue := resp.Header().Get("Server")
   dataValue := resp.Header().Get("Date")

If the header exists, you'll get its first value (keep in mind that there might be multiple values for a single header name); otherwise you'll get an empty string.

2. By using map's methods:

   serverValue, ok := resp.Header()["Server"]
   dataValue, ok := resp.Header()["Date"]

If the header exists, ok will be true (i.e. the header exists) and you'll get a slice of strings containing all the values for that header; otherwise, ok will be false (i.e. the header doesn't exist).

Use whichever method you prefer.

If you need to iterate over all the header values, you can do it with something like:

for name, value := range resp.Header() {
    fmt.Printf("%v: %v\n", name, value)
}

You could use a function like this one:

func HeaderToArray(header http.Header) (res []string) {
    for name, values := range header {
        for _, value := range values {
            res = append(res, fmt.Sprintf("%s: %s", name, value))
        }
    }
    return
}

It should return an array like the one you want.

This solutions is for go version go1.13 windows/amd64.

The request object from http.Request contains Header object. We are using net/http package here. You can get values of all headers by name using following method:

import(
	"net/http"
)

type RequestHeaders struct {
	ContentType      string      `json: "content-type"`
	Authorization    string      `json: "authorization"`
}

func getHeaders(r *http.Request) RequestHeaders {
		contentType := r.Header.Get("Content-Type")
		authorization := r.Header.Get("Authorization")
		headers := RequestHeaders{
						Content-Type: contentType,
						Authorization: authorization}
		return headers
}

You can see that we are using r.Header.Get("Content-Type") method to get value of the header.

If the header is missing the Get() method will return empty string.

You can retrieve the response header's first value with resp.Header().Get(), which returns "" if the header key has no values.

Hence, in your case

var a [2]string
a[0] = resp.Header().Get("server")
a[1] = resp.Header().Get("date")