How to Copy Struct Type Using Value and Pointer Reference in Golang?

Last Updated : 22 Jun, 2020

A structure or struct in Golang is a user-defined data type that allows to combine data types of different kinds and act as a record. A struct variable in Golang can be copied to another variable easily using the assignment statement(=). Any changes made to the second struct will not be reflected back to the first struct. Example 1:

// Golang program to illustrate copying
// a structure to another variable

package main

import (
    "fmt"
)

// declaring a structure
type Student struct{

    // declaring variables
    name string
    marks int64
    stdid int64
}

// main function
func main() {
    
        
    // creating the instance of the 
    // Student struct type 
    std1 := Student{"Vani", 98, 20024}
        
    // prints the student struct
    fmt.Println(std1)
        
    // copying the struct student
    // to another variable by 
    // using the assignment operator
    std2 := std1
        
    // printing copied struct
    // this will have same values 
    // as struct std1
    fmt.Println(std2)
        
    // changing values of struct
    // std2 after copying
    std2.name = "Abc"
    std2.stdid = 20025
        
    // printing updated struct
    fmt.Println(std2)
    
}

Output:

{Vani 98 20024}
{Vani 98 20024}
{Abc 98 20025}

In the case of pointer reference to the struct, the underlying memory location of the original struct and the pointer to the struct will be the same. Any changes made to the second struct will be reflected in the first struct also. Pointer to a struct is achieved by using the ampersand operator(&). It is allocated on the heap and its address is shared. Example 2: