C++ Primer Plus

Freeing Memory with delete

Using new to request memory when you need it is just the more glamorous half of the C++ memory-management package. The other half is the delete operator, which enables you to return memory to the memory pool when you are finished with it. That is an important step toward making the most effective use of memory. Memory that you return, or free, can then be reused by other parts of the program. You use delete by following it with a pointer to a block of memory originally allocated with new:

int * ps = new int; // allocate memory with new. . .               // use the memorydelete ps;          // free memory with delete when done

This removes the memory to which ps points; it doesn’t remove the pointer ps itself. You can ...