c++Does this contain a memory leak

Does the code below contain a memory leak. I suspect it does but the tools I use to detect them(Visual Studio + Parasoft c++ test) aren't flagging up anything. If it is how would I fix it?

//A dynamically allocated array of char pointers
int numOfStrings = 10, numOfChars = 32;
char** data = new char*[numOfStrings];

//Generate each each individual string
for(int i = 0; i <numOfStrings; i++)
    data[i] = new char[numOfChars];

//moves the elements 1-5 in the array to the right by one
int index = 1, boundary = 5, sizeToMove = (boundary - index) * sizeof(numOfChars);
memmove(&data[index + 1],&data[index],sizeToMove);

delete[] data;


I should mention, I have tried iterating over each individual string as below but an exception occurs.

for(int i = 0; i< numOfStrings; i++)
    delete [] data [i];

Yes it does. When you are deleting

delete[] data;

You are releasing the memory allocated for data. However the memory allocated

data[i] = new char[numOfChars];

is still not freed.

You have to iterate over data and delete each data[i] before deleting data.

Generally you should make sure you have as many deletes as news.

Here you have numOfStrings + 1 news and only one delete.

One more leak

Since you are doing

int index = 1, boundary = 5, sizeToMove = (boundary - index) * sizeof(numOfChars);
memmove(&data[index + 1],&data[index],sizeToMove);

(You are not moving shifting five places as you thought but 4 places (5 - 1 = 4))

After this operation

data[2] will get the value of data[1]

data[2] <- data[1]
data[3] <- data[2]
data[4] <- data[3]
data[5] <- data[4]

And what was pointed to by data[5] will be lost.

data[2], data[1] will have the same value (point to the same place)

This can also explain why you are getting segfault when you want to delete by iterating over data

The rule is: for every 'new', there MUST be a corresponding 'delete' call. You don't have that, so you have a leak.

Yes you have a leak!

You have to delete each pointer in the array before deleting the pointer pointing to them.

//delete each array
for(int i = 0; i <numOfStrings; i++)
    delete[] data[i];

//this is a single pointer, not an array
delete[] data;

Now you won't have a leak

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