C++ simple malloc and sizeof

Question

I am getting a weird result with these 2 simple lines

char* reverse = (char*) malloc(sizeof(char)*19);
cout << sizeof(reverse)/sizeof(char) << endl;

No matter what number i put in the first line (in this example, it is 19). I always get 4 as the output. What is wrong ? Thanks.

Answer 1

On 32-bit machine sizeof pointer is 32 bits (4 bytes), while on 64 bit machine it's 8 bytes. Regardless of what data type they are pointing to, they have fixed size.

And

sizeof(char) = 1 byte

So, you are getting 4 every time because your system is a 32-bit machine.