Does Calloc Initialize to 0?

calloc() allocates the memory and also initializes the allocated memory block to zero. If we try to access the content of these blocks then we'll get 0.

Does calloc initialize to 0 or NULL?

calloc returns a pointer to the first element of the allocated elements. If memory cannot be allocated, calloc returns NULL . If the allocation is successful, calloc initializes all bits to 0. In the example above memory allocation of NUMBER_OF_ELEMENTS 32 bit integers is requested by calloc .

Why does calloc initialize allocated memory to 0?

If you need the data zeroed, then calloc() can zero it as efficiently as you can (or, more likely, it can do it more efficiently than you can). @amjad: Using calloc is fulfilling the programmer's responsibility to initialize the memory.