go - Buffer issue cannot use <type> as type io.Reader in argument to http.NewRequest golang -

i having issue when passing string in http.newrequest in golang body param.

the error got :

cannot use req.body (type string) type io.reader in argument http.newrequest: string not implement io.reader (missing read method)

similarly there other use cases buffer required input instead of particular type or array of it. eg, byte[] when input required buffer.

what did error mean , ways of solving , understanding golang trying enforce.

edit: line having issue , did not find references.

http.newrequest(req.method, req.url, req.body)

http.newrequest(req.method, req.url, strings.newreader(req.body)) solves issue. planning add answer (as fyi type of question)

this error means http.newrequest method take io.reader interface body argument:

func newrequest(method, urlstr string, body io.reader) (*request, error)

it done way can pass file, connection server, response else request easily.

the "problem" string doesn't implement io.reader interface, defined follow:

type reader interface {    read(p []byte) (n int, err error) }

its not huge problem, can use strings.reader type wrapper around string implement said interface.

func newreader(s string) *reader

tip: there bytes.reader type times have []byte pass parameter.

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