Golang React JS Technology Blog

Copy Struct Type Using Value and Pointer Reference

r2 will be the same as r1, it is a copy of r1 rather than a reference to it. Any changes made to r2 will not be applied to r1 and vice versa. When r3 is updated, the underlying memory that is assigned to r1 is updated.

Example

package main

import "fmt"

type rectangle struct {
	length  float64
	breadth float64
	color   string
}

func main() {
	r1 := rectangle{10, 20, "Green"}
	fmt.Println(r1)

	r2 := r1
	r2.color = "Pink"
	fmt.Println(r2)

	r3 := &r1
	r3.color = "Red"
	fmt.Println(r3)

	fmt.Println(r1)
}

Output

{10 20 Green}
{10 20 Pink}
&{10 20 Red}
{10 20 Red}
As both r1 and r3 both reference the same underlying memory, their values are the same. Printing the values of r3 and r1 shows that the values are the same.
Most Helpful This Week
Illustration of Checkpoint Synchronization in Golang How append a slice to an existing slice in Golang? Panic: runtime error: index out of range error in Golang Golang program to generate number of slices permutations of number entered by user How to build a map of struct and append values to it? How do you create an HTTP server in Go?