You can’t assign memory to an array. An array has a fixed size, for the whole of its lifespan. An array can never be null. An array is not a pointer. malloc returns the address to a memory block that is reserved for the program. You can’t “assign” that (being the memory block) to an … Read more
From http://wiki.answers.com/Q/Is_it_better_to_use_malloc_or_calloc_to_allocate_memory malloc() is faster, since calloc() initializes the allocated memory to contain all zeros. Since you typically would want to use and initialize the memory yourself, this additional benefit of calloc() may not be necessary.
Contrary what some are saying in their answers, it is possible. char * c = new char[N](); Will zero initialize all the characters (in reality, it’s called value-initialization. But value-initialization is going to be zero-initialization for all its members of an array of scalar type). If that’s what you are after. Worth to note that … Read more
I heard two [mutually exclusive] explanations for why it has two arguments: calloc takes the responsibility for checking for overflow on multiplication. If the total size of the requested block is too large (like overflows size_t), calloc returns null pointer to indicate failure. With malloc you have to watch for overflow yourself, which many people … Read more
It means the file containing main doesn’t have access to the player structure definition (i.e. doesn’t know what it looks like). Try including it in header.h or make a constructor-like function that allocates it if it’s to be an opaque object. EDIT If your goal is to hide the implementation of the structure, do this … Read more
According to an excerpt from the book Linux System Programming (by Robert Love), no official sources exist on the etymology of calloc. Some plausible candidates seem to be: Count or counted, because calloc takes a separate count argument. Clear, because it ensures that the returned memory chunk has been cleared. Brian Kernighan is reported to … Read more
In C++ classes/structs are identical (in terms of initialization). A non POD struct may as well have a constructor so it can initialize members. If your struct is a POD then you can use an initializer. struct C { int x; int y; }; C c = {0}; // Zero initialize POD Alternatively you can … Read more
calloc() gives you a zero-initialized buffer, while malloc() leaves the memory uninitialized. For large allocations, most calloc implementations under mainstream OSes will get known-zeroed pages from the OS (e.g. via POSIX mmap(MAP_ANONYMOUS) or Windows VirtualAlloc) so it doesn’t need to write them in user-space. This is how normal malloc gets more pages from the OS … Read more