遍历go结构以获得csv字符串[重复]

Question

This question already has an answer here:

• Iterate through the fields of a struct in Go 2 answers

I have a struct representing a dataset that I need to write to a CSV file as a time-series data. This is what I have so far.

type DataFields struct {
    Field1 int,
    Field2 string,
    ...
    Fieldn int
}

func (d DataFields) String() string {
    return fmt.Sprintf("%v,%v,...,%v", Field1, Field2,..., Fieldn)
}

Is there a way I can iterate through the members of the struct and construct a string object using it?

Performance is not really an issue here and I was wondering if there was a way I could generate the string without having to modify the String() function if the structure changed in the future.

EDITED to add my change below:

This is what I ended up with after looking at the answers below.

func (d DataFields) String() string {
    v := reflect.ValueOf(d)
    var csvString string
    for i := 0; i < v.NumField(); i++ {
        csvString = fmt.Sprintf("%v%v,", csvString, v.Field(i).Interface())
    }

    return csvString
}

</div>

Answer 1

What you are looking for is called reflection. This answer explains how to use it to loop though a struct and get the values.

This is the example the author uses on the other answer:

package main

import (
    "fmt"
    "reflect"
)

func main() {
    x := struct{Foo string; Bar int }{"foo", 2}
    v := reflect.ValueOf(x)
    values := make([]interface{}, v.NumField())

    for i := 0; i < v.NumField(); i++ {
        values[i] = v.Field(i).Interface()
    }

    fmt.Println(values)
}

You can see it working on the go playground.