C Programming - Memory Allocation - Discussion

malloc() and calloc() are used to allocate space in memory but one difference is there allocating methods.

malloc() : malloc(int) only passing one arguments int allocates 2 bytes.

calloc() : calloc(int,5) passing two arguments int allocates 2 bytes, also 5 times 2 bytes will allocates.

@Lijina. What is malloc() and calloc() ?

Can you explain with example program ?

free() : Releases the specified block of memory back to the system.

Also Calloc() initialize the allocated memory to zero, while malloc() doesn't.

Can anybody explain what is free() and farfree()?

Is the following statement a declaration or definition?

extern int i;

A. Declaration B. Definition
C. Function D. Error

Answer & Explanation

Answer: Option A.

Explanation:

Declaring is the way a programmer tells the compiler to expect a particular type, be it a variable, class/struct/union type, a function type (prototype) or a particular object instance. (ie. extern int i).

Declaration never reserves any space for the variable or instance in the program's memory; it simply a "hint" to the compiler that a use of the variable or instance is expected in the program. This hinting is technically called "forward reference".

Memory allocated by malloc or calloc : deallocated by free().
Memory allocated by new(in c++) : deallocated by delete().

What is the purpose of malloc?

Explain malloc and calloc with example?

Memory allocated by malloc and calloc are deallocated by free in C.