A memory leak occurs when heap memory is no longer needed but is not returned for reuse. In a C++ program, losing the last pointer to an allocated array without freeing it can leave that memory unavailable. Repeated allocations may eventually exhaust the heap. section 10.3.4
Listing 10.8 C++ code to read numbers into a dynamic array
int* readNInts(int count) {
int* ptr; #1
ptr = new int[count]; #2
for (int i = 0; i < count; i++) {
ptr[i] = readInt(); #3
}
return ptr; #4
}
The C++ function allocates an array with `new` and returns its pointer. Whoever finishes using the array must release it with `delete[]`; losing the pointer first makes that allocation a leak. section 10.3.4
Explicit memory management offers control but adds work to development and testing because leaks can be difficult to find. C# arrays are also allocated on the heap, but .NET uses a garbage collector to manage memory instead of requiring this `delete[]` step. section 10.3.4
