Programming Language

What Is A Memory Leak In C++?

A memory leak generally occurs when pieces or just a single piece of memory that was allocated by a programmer previously is not deallocated properly by the programmer. Although, the program is not using that memory any longer, it is still in the reserved mode and you cannot use that piece of memory until it is deallocated by the programmer properly. This is why, it is known as a memory leak, since it is just like a leaky faucet in which water is being wasted, however, in this case, this is about computer memory.

The Common Error In Programming- Memory Leaks

When you are using languages that possess no built in the automatic garbage collection, for example, C++ and C, memory leaks are a common error. Generally, this error occurs as dynamically owed memory has become difficult to get to.

The occurrence of memory leak bugs has resulted in the formation of several debugging tools for detecting unreachable memory. Some of the common debuggers for C++ and C programs are as follows.

  • Memwatch
  • Memory
  • IBM Rational Purify
  • Insure++
  • BoundsChecker
  • Parasoft
  • Valgrind

The capabilities of a “Conservative” garbage can be added to any programming language that does not have libraries and a built-in feature for doing this, are available for C++ and C programs.


Major Problems Because Of Memory Leaks

The main issues caused by a memory leak in C++ include the following.

  • Memory leaks leave chunk(s) of memory not available for use by the programmer.
  • In case, a program has a lot of deallocated memory, then that could slow down the program’s performance.
  • Another issue is that if there’s no memory left in the program due to memory leaks, then that could cause the program to crash of course.

Example Of A Memory Leak In C++

The following display a memory leak in C++:

The Pointer is Out of Scope:

void memLeak( )


int *data = new int;

*data = 15;



Thus, the issue with the above code is that you can never delete the “*data” pointer. This clearly means that the data it references is never allocated again, which leads to memory wastage.



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