What is Memory Leak in C/C++?

The memory leak occurs, when a piece of memory which was previously allocated by the programmer. Then it is not deallocated properly by programmer. That memory is no longer in use by the program. So that place is reserved for no reason. That’s why this is called the memory leak.

For the memory leak, some block of memory may have wasted. If the system has enough memory, in that case also this may slow down the performance.

Example

void my_func() {
   int *data = new int;
   *data = 50;
}

Here the problem is *data pointer is never deleted, so memory is wasted.

Example

#include <stdio.h>
main(void) {
   auto int my_fun();
   my_fun();
   printf("Main Function\n");
   int my_fun() {
      printf("my_fun function\n");
   }
   printf("Done");
}

Output

my_fun function
Main Function
Done