Prerequisite: Pointers in Go
Pointers in Go programming language or
Golang is a variable which is used to store the memory address of another variable. A pointer is a special variable so it can point to a variable of any type even to a pointer. Basically, this looks like a chain of pointers. When we define a pointer to pointer then the first pointer is used to store the address of the second pointer. This concept is sometimes termed as
Double Pointers.
How to Declare a pointer to pointer in Golang?
Declaring Pointer to Pointer is similar to declaring
pointer in Go. The difference is we have to place an additional ‘
*’ before the name of pointer name. This is generally done when we are declaring the pointer variable using the
var keyword along with the type. Below example and image will explain the concept in much better way.
Example 1: In the below program the pointer
pt2 stores the address of
pt1 pointer. Dereferencing
pt2 i.e.
*pt2 will give the address of variable
v or you can also say the value of pointer
pt1. If you will try
**pt2 then this will give the value of the variable
v i.e. 100.
👁 Double Pointer in Go
Output:
The Value of Variable V is = 100
Address of variable V is = 0x414020
The Value of pt1 is = 0x414020
Address of pt1 is = 0x40c128
The value of pt2 is = 0x40c128
Value at the address of pt2 is or *pt2 = 0x414020
*(Value at the address of pt2 is) or **pt2 = 100
Example 2: Let's make some changes in the above program. Assigning some new value to the pointers by changing the value of pointers using dereferencing as shown below:
👁 How Pointers Works In Go
Output:
The Value of Variable v is = 100
Value stored in v after changing pt1 = 200
Value stored in v after changing pt2 = 300
