---
title: "Describe the errors when using a pointer after its memory has been deallocated."  
description: "Describe the errors when using a pointer after its memory has been deallocated."  
author: "Revati S Misra"  
published: 2023-08-16  
updated: 2023-08-17  
canonical: https://www.mindstick.com/forum/159538/describe-the-errors-when-using-a-pointer-after-its-memory-has-been-deallocated  
category: "visual c++"  
tags: ["exception", "c++", "memory management"]  
reading_time: 2 minutes  

---

# Describe the errors when using a pointer after its memory has been deallocated.

[Describe](https://www.mindstick.com/interview/12752/what-is-ddms-describe-some-of-its-capabilities) the [errors](https://answers.mindstick.com/qa/116170/fresh-fir-against-gandhis-in-national-herald-case-cover-up-for-ed-s-own-errors) when using a [pointer](https://www.mindstick.com/articles/11/pointers) after its [memory](https://www.mindstick.com/blog/300050/what-causes-sudden-memory-loss) has been deallocated.

## Replies

### Reply by Aryan Kumar

Sure. When you use a pointer after its memory has been deallocated, it is called a dangling pointer. A dangling pointer is a pointer that points to an area of memory that has been freed.

Dangling pointers can cause several errors, including:

- **Segmentation fault:** A segmentation fault is a type of error that occurs when the program tries to access memory that it does not have access to. This can happen if the pointer points to an area of memory that has been deallocated.
- **Data corruption:** If the program tries to write to the memory that the pointer points to, it can corrupt the data that is stored there. This can cause the program to crash or produce incorrect results.
- **Security vulnerabilities:** Dangling pointers can be used to create security vulnerabilities in programs. For example, an attacker could exploit a dangling pointer to gain access to sensitive data or to execute arbitrary code.

To avoid these errors, it is important to make sure that you do not use a pointer after its memory has been deallocated. You can do this by:

- Using a smart pointer instead of a raw pointer. Smart pointers automatically deallocate the memory that they point to when they go out of scope.
- Checking if the pointer is null before you use it. A null pointer is a pointer that does not point to any memory. If you check if the pointer is null before you use it, you can avoid trying to use a dangling pointer.
- Using the `delete` keyword to deallocate the memory that a pointer points to. This will prevent the pointer from becoming a dangling pointer.

It is important to be aware of the dangers of dangling pointers and to take steps to avoid them. By following these tips, you can help to protect your programs from errors and security vulnerabilities.


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Original Source: https://www.mindstick.com/forum/159538/describe-the-errors-when-using-a-pointer-after-its-memory-has-been-deallocated

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