C++ Academy · Lesson

Common Memory Bugs

Avoid leaks and dangling pointers.

Memory Leaks

A memory leak happens when heap memory is allocated but never freed. The program keeps consuming memory it can no longer reach.

void leak() {
    int* p = new int(5);
    // missing delete p;  -> leaked
}

A dangling pointer points to memory that has already been freed. Dereferencing it is undefined behavior.

int* p = new int(7);
delete p;
// *p = 3;   // BUG: dangling access