A pointer in a simple sense is a variable that stores the address of a value in computer memory ‘RAM’, to store the address we need to get the address using the ampersand operator & which is the address of the operator, the pointer variable is declared using * and name of the variable after the data type.
The address of value output is always in hexadecimal i.e 0x02ab457f of the sort, hexadecimals are numbers in base 16 unlike decimals in base 10, which ranges from 0 — F, i.e 0,1,2,3,4,5,6,7,8,9, A, B, C, D, E, F which is basically 0 through 15. The highest count for hex is FF which is 255 in decimal and 11111111 in binary.
#include <stdio.h>
int main(void)
{
int n = 50;
int *p = &n;
/*& address of operator in C*/ // *p signifies a pointer because of
// the asterick before the letter
printf("%p\n", p); // %p -> pointers placeholders in c
printf("%i\n", *p); // going into the pointers which means deference operator
}
A pointer is a variable that stores the address or location in memory of some values (using &ersand operator).
Now let's use the above code to explain pointers and dereferencing.
Inside the main function, we declared the two variables n and p in the static, though the pointer can also be stored on the heap, buts let's not go there now, we will talk about it later.
n is a normal variable storing the value 50 and p with the asterisk (*) before which makes a pointer variable storing the address of n in memory which was obtained using the ampersand operator. Think of it like n is a box on a table that has something in it and that something is a value or in this case an int value of 50, so the content of the box is an int value 50 and the location is on the table, thus from this where do you think the box 'n' is located? in let's say a room..... answer is on the table which is the address, and the table can only be stored inside a pointer if you intend to use it, So the room is the RAM and the table is the byte(s) space address in the memory and this address is stored in a pointer.
Moreso, pointers point to an address.
To print out the pointer with the print function we use the %p as the format code in quotes, then pass the pointer variable as the second or last argument without the asterisk this time or every other time when want to just get the address after the initial declaration.
To get the content in the address the pointer variable is storing we use the dereferencing operator which is adding * to the pointer variable, which means go to that address you are storing and get me whatever is inside, so if the table was the address again go to the table and grab whats there, that is the box.
0x7ffdb86f7c9c (address)
50 (the content of the address)
That's all for now.
Thank you for reading