在下面的代碼中：package mainimport (    "bytes"    "encoding/json"    "fmt")type Student struct {    Firstname, lastname string    Email               string    Age                 int    HeightInMeters      float64    IsMale              bool}func main() {    john := Student{        Firstname:      "John",        lastname:       "Doe",        Age:            21,        HeightInMeters: 1.75,        IsMale:         true,    }    johnJSON, _ := json.Marshal(john) // johnJSON is of type []byte    fmt.Println(string(johnJSON))     // print it in characters}johnJSON, _ := json.Marshal(john)john正在將 struct type( )編碼為[]byte.在下面的代碼中：package mainimport (    "bytes"    "encoding/json"    "fmt")type Student struct {    Firstname, lastname string    Email               string    Age                 int    HeightInMeters      float64    IsMale              bool}func main() {    john := Student{        Firstname:      "John",        lastname:       "Doe",        Age:            21,        HeightInMeters: 1.75,        IsMale:         true,    }    // johnJSON, _ := json.Marshal(john) // johnJSON is of type []byte    // fmt.Println(string(johnJSON))     // print it in characters    // create a buffer to hold JSON data    buf := new(bytes.Buffer)    // create JSON encoder for `buf`    bufEncoder := json.NewEncoder(buf)    bufEncoder.Encode(john)    // print contents of the `buf`    fmt.Println(buf) // calls `buf.String()` method}bufEncoder.Encode(john)正在將 struct type( john) 編組為io.Writertype( buf)何時使用json.Marshal()vs Encoder.Encode()？因為buf兩者johnJSON都是[]byte類型type Buffer struct {    buf      []byte // contents are the bytes buf[off : len(buf)]    off      int    // read at &buf[off], write at &buf[len(buf)]    lastRead readOp // last read operation, so that Unread* can work correctly.}