Golang how to print structure value using pointer

Basically, you have to do it yourself. There are two ways to do this. Either just print what you need, or implement an interface Stringer

for the structure by adding func String() string

which is called when the format is used %v

. You can also refer to each value in a format that is a structure.

Implementing an interface Stringer

is the surest way to always get what you want. And you need to do it once for each structure instead of the format string when printing. In the meantime, there is no need to know about it. ”

https://play.golang.org/p/PKLcPFCqOe

package main

import "fmt"

type A struct {
    a int32
    B *B
}

type B struct{ b int32 }

func (aa *A) String() string {
    return fmt.Sprintf("A{a:%d, B:%v}",aa.a,aa.B)
}

func (bb *B) String() string {
    return fmt.Sprintf("B{b:%d}",bb.b)
}

func main() {
    a := &A{a: 1, B: &B{b: 2}}

    // using the Stringer interface
    fmt.Printf("v ==== %v \n", a)

    // or just print it yourself however you want.
    fmt.Printf("v ==== A{a:%d, B:B{b:%d}}\n", a.a, a.B.b)

    // or just reference the values in the struct that are structs themselves
    // but this can get really deep
    fmt.Printf("v ==== A{a:%d, B:%v}", a.a, a.B)
}