memset,malloc,alloc

[sharath137]

hi,

Can anyone tell me the exact difference between memset,malloc and calloc.I am new to c++, Know this is simple question to ask in c++ but i am getting lot of confusions in using them and i want to knw whr exactly i can use these.

Regards,
Sharath.

[Peter87]

These function is mostly used in C.

memset sets the bytes in a block of memory to a specific value.

malloc allocates a block of memory.

calloc, same as malloc. Only difference is that it initializes the bytes to zero.

In C++ the preferred method to allocate memory is to use new.
C: int intArray = (int*) malloc(10 * sizeof(int));
C++: int intArray = new int[10];

C: int intArray = (int*) calloc(10 * sizeof(int));
C++: int intArray = new int[10]();

[sharath137]

Thks for the quick reply....

Can u please tell me where exactly can we use these three..

for example if we use a structure wat to use to assign...

[lukecian]

malloc and free pair are not recommended for object mem allocation in c++

for allocating object's mem blocks , use key word new
for recycling mem blocks ,use delete correspondingly

malloc and free know nothing about class information

but new and delete do .

malloc --- simply get you some mem blocks in bytes without cleaning to zero

calloc -----get you some mem blocks that is initialized all with zero

that is the difference between them.


here is an example:http://www.diffen.com/difference/Calloc_vs_Malloc

[sharath137]

tks for ur reply guys....