Rahul 06 Jul Both are used for dynamic memory allocation. Malloc takes single argument but calloc takes two. Malloc doesn't initialize the memory but calloc initialize the memory zero.
View all vote's. No Down Vote. Richa 03 Dec Following are the main difference between malloc and calloc. Memory allocated by calloc is initialized to zero while memory allocated by malloc contains garbage value. Read More. No Vote. No Up Vote. Sujeet 16 May M alloc: 1. The name malloc stands for memory allocation. Calloc 1. The name Calloc stands for contiguous allocation. Mishra 14 Jul malloc and calloc are library functions that allocate memory dynamically at run time which means during the execution of program we can allocate memory by using these library functions malloc - Memory Allocation it allocates memory block of given size and returns a pointer at the beginning of the block calloc - contiguous allocation it allocates memory and initializes the allocated memory block to zero.
Differences between malloc and calloc - 1-The name malloc stands for memory allocation. The name calloc stands for contiguous allocation. If the space assigned by malloc is overrun, the results are undefined. The storage is initialized to zero. If the allocation succeeds, a void pointer to the allocated memory is returned.
Otherwise NULL is returned. The allocated region is initialized to zero. However, in practice the difference in speed is very tiny and not recognizable. Dheeraj 11 Jul M alloc: 1. Anirban 09 Jul Function: calloc allocates a region of memory large enough to hold "n elements" of "size" bytes each. Also initializes contents of memory to zeroes. Malloc allocates "size" bytes of memory. Basis of comparison malloc calloc No of blocks Assigns single block of demanded memory.
Assigns multiple blocks of the requested memory. The allocated memory is initialized to zero by using calloc. Manner of Allocation malloc function allocates memory of size 'size' from the heap.
Speed Fast Comparatively slow. The malloc function assigns a block of memory in bytes. The user should explicitly give the block size, it requires for the use. Through malloc function program requests RAM of the system for allocation of the memory, if the request is conceded i. It returns void type of pointer, that means any type of pointer can be assigned.
Although, it returns a NULL , if the malloc functions is not able to allocate the required amount of memory. Where size represents the size of memory required in bytes i. If the memory space allocated by the malloc function has not been used before, each of them may be 0; otherwise, if this part of the memory space has been allocated, freed, and reallocated, various Kind of data.
That is to say, the program that uses the malloc function can run normally at the beginning the memory space has not been reallocated , but after a period of time the memory space has been reallocated , problems may occur.
The calloc function initializes each bit in the allocated memory space to zero, that is, if you allocate memory for elements of character type or integer type, then these elements will be guaranteed to be initialized to zero; If you are allocating memory for pointer-type elements, then these elements are usually but not guaranteed initialized to null pointers; if you are allocating memory for real-type elements, then these elements may only in some computers Will be initialized to floating point zeros.
Another difference between the malloc function and the calloc function is that the calloc function returns an array of certain objects, but the malloc function returns only one object. In order to clearly allocate memory space for an array, some programmers will choose calloc function. However, apart from whether to initialize the allocated memory space, most programmers believe that there are no differences between the following two function call methods:.
It should be explained that theoretically according to the ANSIC standard arithmetic operations on pointers can only be performed in a specified array, but in practice, even if C compilers or translators follow this rule, many C programs break This restriction. Therefore, although the malloc function cannot return an array, the memory space it allocates can still be used by an array the same is true for the realloc function, although it cannot return an array.
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