Updated on February 7, 2024

How to Print the Memory Address of a Variable in Go

In this article, you’ll learn different ways to print the memory address of a variable in Go. This is useful when you want to find out the location in memory of a variable perhaps in order to compare it to something else when debugging your code.

The easiest way to print the memory address of a variable is to pass a pointer to the variable to the fmt.Println() method:

func main() {
	a := 2
	fmt.Println(&a)
}

output

0xc0000b6000

When using a print formatted method (like fmt.Printf()), you may use the %p verb to obtain the address of a variable like this:

func main() {
	a := 2
	fmt.Printf("The address of a is: %p\n", &a)
}

output

The address of a is: 0xc0000b6000

The above methods work for variables of any data type:

func main() {
	a := 2
	b := "a string"
	c := map[string]int{
		"a": 1,
	}
	d := struct {
		name string
		age  int
	}{
		"John", 20,
	}
	e := true
	f := func() {
		fmt.Println("hello world")
	}
  g := &f
  h := []int{1, 2, 3}
  i := h[0]

	fmt.Printf("The address of a is: %p\n", &a)
	fmt.Printf("The address of b is: %p\n", &b)
	fmt.Printf("The address of c is: %p\n", &c)
	fmt.Printf("The address of d is: %p\n", &d)
	fmt.Printf("The address of e is: %p\n", &e)
	fmt.Printf("The address of f is: %p\n", &f)
	fmt.Printf("The address of g is: %p\n", &g)
	fmt.Printf("The address of h is: %p\n", &h)
	fmt.Printf("The address of i is: %p\n", &i)
}

output

The address of a is: 0xc00001a0e0
The address of b is: 0xc000010250
The address of c is: 0xc00000e028
The address of d is: 0xc00000c030
The address of e is: 0xc00001a0e8
The address of g is: 0xc000120018
The address of h is: 0xc00001a0e0
The address of i is: 0xc0000b6000

But note that you cannot take the address of a literal, map value, or function return value. The compiler will show an error if you attempt to do so:

func main() {
	f := func() string {
		return "hello world"
	}

	fmt.Printf("The address of f() is: %p\n", &f())
}

output

./main.go:12:45: invalid operation: cannot take address of f() (value of type string)

Removing the 0x prefix from the memory address

The 0x prefix in a memory address is used to indicate that the address is in hexadecimal form. If you’d like to print the memory address of a variable without the 0x prefix, use the %#p verb as shown below:

func main() {
	a := 1

	fmt.Printf("The address of a is: %p\n", &a)
	fmt.Printf("The address of a is: %#p\n", &a)
}

output

The address of a is: 0xc00001a0e0
The address of a is: c00001a0e0

Comparing memory address values

The == operator can be used to compare memory addresses in Go:

func main() {
	a := 1
	b := &a
	c := b

	fmt.Println(&a == c)
}

output

true

Thanks for reading, and happy coding!

#golang