How to Print a Struct\'s Nested Pointer Value in Golang Without the Pointer Address?

How to Print Struct Value with Pointer in Golang

Consider the following code snippet:

package main

import "fmt"

type A struct {
    a int32
    B *B
}
type B struct {
    b int32
}

func main() {
    a := &A{
        a: 1,
        B: &B{
            b: 2,
        },
    }
    fmt.Printf("v ==== %+v \n", a) // output: v ==== &{a:1 B:0xc42000e204}
}

Here, you want to print the value of B without its pointer representation. To achieve this, there are a few options:

1. Implementing the Stringer Interface:

The fmt.Printf() function calls the String() method if it exists for the type being printed. Implement the String() method for both A and B structures:

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)
}

With this implementation, the output will be:

v ==== A{a:1, B:B{b:2}}

2. Customizing the Print Format:

You can directly format the output string to include only the desired fields:

fmt.Printf("v ==== A{a:%d, B:B{b:%d}}\n", a.a, a.B.b)

Output:

v ==== A{a:1, B:B{b:2}}

3. Referencing Values in the Struct:

Since B is a field within A, you can directly reference its value:

fmt.Printf("v ==== A{a:%d, B:%v}", a.a, a.B)

Output:

v ==== A{a:1, B:&{b:2}}

The above is the detailed content of How to Print a Struct\'s Nested Pointer Value in Golang Without the Pointer Address?. For more information, please follow other related articles on the PHP Chinese website!