Pointer operations

Read operation on a pointer

Given a pointer:

char* address1 = (char*) 0x00007FFF8E3C3824;

to read the data stored in that address, we need to dereference it, like this:

char data = *address1;   // Dereferencing a pointer to read data

With the result being that 1 byte of data is read from the pointer and stored into the data variable.

Write operation on a pointer

To write data to a pointer the address must be dereferenced

*address1 = 0x89;   // Dereferencing a pointer to write data

This assigns the value 0x89 to the address being pointed at.

Example:

#include <iostream>

int main(){
    // Create an int type variable and initialize it to value 100
    int variable1 = 100;
    
    // Print the address of the above variable
    std::cout<<"Address of variable1 = "<<&variable1<<std::endl;
    
    // Create a pointer variable and store the address of the above variable
    int* variable1_ptr = &variable1;
     
    // Perform read operation on the pointer variable to fetch 1 byte of data from the pointer
    int read_variable1 = *variable1_ptr;
     
    // Print the data obtained from the read operation on the pointer.
    std::cout<<"Fetch 1 byte of data = "<<read_variable1<<std::endl;
     
    // Perform write operation on the pointer to store the value 65
    *variable1_ptr = 65;
    
    // Print the value of the variable defined in step 1
    std::cout<<"Value of variable = "<<*variable1_ptr<<std::endl;
    
    return 0;
}

Output:

Address of variable1 = 0x7ffd2ac75208
Fetch 1 byte of data = 100
Value of variable = 65