How To Print Struct Fields in Go

Sentry Answers>Go>

Clive B.

—October 15, 2024

The Problem

You don’t know how to see the values that a struct contains.

The Solution

Because struct fields in Go are just values, printing them out can be as simple as printing any variable:

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package main

import "fmt"

type Example struct {
    ID    int
    Title string
}

func main() {
    example := Example{
        ID:    42,
        Title: "Example title",
    }

    fmt.Printf("example struct: ID: %d, Title: %s", example.ID, example.Title)

This prints:

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example struct: ID: 42, Title: Example title

Printing the Entire Struct

If you want to print the entire struct and include its field names automatically, you can use a special verb to do so:

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package main

import (
    "encoding/json"
    "fmt"
    "log"
)

type Example struct {
    ID    int
    Title string
    List  []int
}

func main() {
    example := Example{
        ID:    42,
        Title: "Example title",
        List:  []int{1, 2, 3},
    }

    fmt.Printf("%+v", example)
}

This prints:

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{ID:42 Title:Example title List:[1 2 3]}

Alternatively, if you want to print something easier to see over multiple lines, you can use the json.MarshallIndent function to print it as indented JSON:

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func main() {
    example := Example{
        ID:    42,
        Title: "Example title",
        List:  []int{1, 2, 3},
    }

    bytes, err := json.MarshalIndent(example, "", "\t")
    if err != nil {
        log.Fatal("failed to marshal example", err)
    }

    fmt.Println(string(bytes))
}

This prints:

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{
  "ID": 42,
  "Title": "Example title",
  "List": [
    1,
    2,
    3
  ]
}

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How To Print Struct Fields in Go

The Problem

The Solution

Printing the Entire Struct

Further Reading

Unsnag Your Mobile Monitoring: Why Teams Are Switching to Sentry

How To Print Struct Fields in Go

The SolutionThe Solution

Printing the Entire StructPrinting the Entire Struct

Further ReadingFurther Reading

The Solution

Printing the Entire Struct

Further Reading