About
Data Type - Pointer (Locator) in Go
In Go, Pointers are explicitly visible.
- The & operator yields the address of a variable,
- and the * operator retrieves the variable that the pointer refers to
but there is no pointer arithmetic.
Articles Related
Properties
- The zero value for a pointer of any type is nil.
- The test p != nil is true if p points to a variable.
- Pointers are comparable; two pointers are equal if and only if they point to the same variable or both are nil.
Operator
The address operator (&)
If a variable is declared var x int
var x int := 1;
The below expression &x (pronounced address of x) yields a pointer to the integer variable, that is, a value of type *int, which is pronounced pointer to int
p := &x // p, of type *int, points to x
We say:
- p points to x
- or equivalently p contains the address of x
Expressions that denote variables are the only expressions to which the address-of operator & may be applied.
Let op ! Each call of f returns a distinct value. See Go - Alias
func f() *int {
v := 1
return &v
}
fmt.Println( f() = = f()) // "false"
The variable operator (*p)
The variable to which p points is written *p. The expression *p yields the value of that variable, an int.
fmt.Println(*p) // "1"
Since *p denotes a variable, it may also appear on the left-hand side of an assignment, in which case the assignment updates the variable.
*p = 2 // equivalent to x = 2
fmt.Println(x) // "2"