Understanding pointers in Go

#go #pointers

We define a variable with a value and a name. The variable name will be converted to a memory address and the value gets stored in that address. In case of a pointer variable, an actual memory address of another variable is stored as a value.

The two unary pointer operators.

& is used to get the memory address of a variable
* is used to get value at the address stored by a pointer variable.

Example:

func main() {
    x := 7
    y := &x // creating a pointer variable

    p := fmt.Println
    pf := fmt.Printf

    pf("type of x (non pointer variable) = %T\n", x)
    p("value of x (stores actual data) =", x)
    p("address of x (memory address where x is located) =", &x)
    // invalid operation: cannot indirect x (variable of type int)
    // p("value dereferenced by x =", *x)

    p()
    pf("type of y (pointer variable) = %T\n", y)
    p("value of y (stores memory address of x) =", y)
    p("address of y (memory address where y is located) =", &y)
    p("value at the address stored by y (dereferencing the pointer) =", *y)
}

Output

type of x (non pointer variable) = int
value of x (stores actual data) = 7
address of x (memory address where x is located) = 0xc00001a0e8

type of y (pointer variable) = *int
value of y (stores memory address of x) = 0xc00001a0e8
address of y (memory address where y is located) = 0xc000012028
value at the address stored by y (dereferencing the pointer) = 7

Resources: