Do I Need Pointers to Access Map Addresses in Go?

How to Access Map Addresses in Go

When working with maps in Go, there may be instances where you need to access their addresses directly. While you may attempt to achieve this using pointers, it's important to understand that this is not necessary as maps are reference types in Go.

Why Pointers to Maps Are Unnecessary

Maps in Go are not passed by value but rather by reference. This means that when you assign a map to a variable, you are actually creating an alias for the original map. Any changes made through either variable will be reflected in the underlying map.

Code Example

Consider the following code snippet:

package main

import "fmt"

func main() {
    valueToSomeType := map[uint8]int{1: 10, 2: 20}
    nameToSomeType := map[string]string{"John": "Doe", "Jane": "Smith"}

    fmt.Println("Original valueToSomeType:", valueToSomeType)
    fmt.Println("Original nameToSomeType:", nameToSomeType)

    // No need for pointers, as maps are passed by reference.
    modifyMap(valueToSomeType, nameToSomeType)
}

func modifyMap(val map[uint8]int, name map[string]string) {
    val[3] = 30
    name["John"] = "Johnson"
}

In this code, no pointers are used to access the maps. However, the function modifyMap still modifies the maps successfully because of their reference nature.

Output

Original valueToSomeType: map[uint8]int{1:10, 2:20}
Original nameToSomeType: map[string]string{John:Doe Jane:Smith}
Modified valueToSomeType: map[uint8]int{1:10, 2:20, 3:30}
Modified nameToSomeType: map[string]string{John:Johnson Jane:Smith}

As you can see, the original maps are modified without the use of pointers.

The above is the detailed content of Do I Need Pointers to Access Map Addresses in Go?. For more information, please follow other related articles on the PHP Chinese website!