A pointer is a variable that stores the address of another variable. The general form of a pointer variable declaration is:
A newly declared pointer which has not been assigned to a variable has the nil value.
The address-of operator &, when placed before a variable gives us the memory address of the variable.
With pointers, we can pass a reference to a variable (for example, as a parameter to a function), instead of passing a copy of the variable which can reduce memory usage and increase efficiency.
Go Pointer Example 1
x = 0
Go Pointer Example 2
Before change ptr 0 After change ptr 10