C++ new * char aren't empty

Question

I had one question.

I developing server in ASIO and packets are in pointed char.

When i create new char (ex. char * buffer = new char[128];) i must clean it manually to nulls.

By:

for(int i =0;i<128;i++)
{
buffer[i] = 0x00;
}

I doing something wrong, that char isn't clear ?

Answer 1

There are two types of ways of calling the new operator in C++ - default initialised and zero initialised.

To default initialise (which will leave the value undefined) call:

int * i = new int;

It is then undefined behavoir to read or use this value until its been set.

To zeroinitialise (which will set to 0) use:

int * i = new int();

This also works with arrays:

int * i = new int[4]; // ints are not initialised, you must write to them before reading them
int * i = new int[4](); // ints all zero initialised

There's some more info here

Answer 2

You do not have to loop over an array of un-initialized values. You can dynamically instantiate array of zeros like this:

char * buffer = new char[128](); // all elements set to 0
                             ^^