C++ Pointers Memory Management

Pointer is a fundamental feature of C++ programming language. Pointers allow you to store and manipulate the memory addresses of variables, functions and data structures. C++ pointers are also used for dynamic memory management, which gives you greater control over memory allocation and deallocation.

Syntax

The syntax for declaring a pointer in C++ is as follows:

data_type *pointer_name;

Here, data_type is the data type of the variable or function that the pointer is pointing to, and pointer_name is the name of the pointer.

Example

#include <iostream>
using namespace std;

int main() {
   int num = 10;
   int *ptr = &num;

   cout << "Value of num: " << num << endl;
   cout << "Value of ptr: " << ptr << endl;
   cout << "Value pointed by ptr: " << *ptr << endl;

   return 0;
}

Output

Value of num: 10
Value of ptr: 0x7ffd9f8a4d5c
Value pointed by ptr: 10

Explanation

In the above example, we have declared an integer variable num, initialized it with a value of 10, and then declared an integer pointer ptr initialized with the address of num. We then output the value of num, the address of ptr and the value pointed to by ptr.

Use

Pointers are used in C++ for a variety of purposes, including:

• Dynamic memory allocation and deallocation
• Passing arguments to functions by reference
• Implementing data structures like linked lists and trees
• Accessing hardware and memory-mapped registers

Important Points

• Always initialize pointers with a valid memory address before using them.
• Avoid dereferencing a null pointer, as it can result in a runtime error.
• Memory allocated using new must be deallocated using delete, otherwise it will lead to memory leaks.

Summary

In this tutorial, we have covered the basics of C++ pointers and their usage in memory management. We have seen how pointers are used for dynamic memory allocation, accessing hardware and memory-mapped registers, passing arguments to functions by reference, and implementing data structures like linked lists and trees. It is important to use pointers with caution and always ensure that they are properly initialized and deallocated to avoid memory leaks.