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Documentation Index

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In this article, we explore two essential operators for working with pointers in Go: the Address Operator and the Dereference Operator. A pointer in Go holds the memory address of a variable. To obtain this memory address, you use the Address Operator, represented by the ampersand (&). Conversely, the Dereference Operator, denoted by an asterisk (*), accesses the value stored at that memory address. Consider the following example. Suppose we have a variable x assigned the value 77. The variable x is stored at a specific memory location. When you apply the Address Operator (i.e., &x), it returns the memory address of x (for example, 0x0301). Placing the Dereference Operator in front of the memory address (*0x0301) retrieves the value stored at that location, which is 77. 
x := 77
&x = 0x0301
*0x0301 = 77
In this example, the memory address (e.g., 0x0301) is illustrative. Actual memory addresses will vary when you run the program.

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A Practical Example in a Go Program

Let’s see how these operators are used in a simple Go program. In this example, we define the main function, create a variable i with the value 10, and then print both the type and value of its address. We further demonstrate dereferencing the address of i to print its original value. 
package main
import "fmt"

func main() {
    i := 10
    // Print the type and value of the address of i.
    fmt.Printf("%T %v\n", &i, &i)
    // Dereference the address to obtain and print the value stored at that address.
    fmt.Printf("%T %v\n", *(&i), *(&i))
}
When you run this program, the output is as follows: 
>>> go run main.go
*int 0xc00018c008
int 10
The first output line shows the type of &i as *int (a pointer to an integer) along with its memory address. The second output line demonstrates that dereferencing this address using *(&i) retrieves the integer value 10.
Notice the distinction between the asterisk used in the Dereference Operator and the asterisk seen in the type output (*int). They serve different purposes in the code and the output.

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Conclusion

This article demonstrated how pointers work in Go with the Address and Dereference Operators. Understanding these concepts is crucial for effectively managing memory and performing low-level operations in Go. Happy coding, and check out more Go tutorials for further learning!

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