Question

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Do I cast the result of malloc?
What is the Best Practice for malloc?

Im new with c language and i have a question
as i was explained in class:

The type of the pointer returned by malloc() is void *, and therefore
we need to cast it into the required type

which means i need to do:

char *str;
str = (char *) malloc(14);

but i dont understand, is it a must? lets say malloc returns that void pointer, why do i see many of examples around without doing the casting? an example:

float *arr = malloc (20 * sizeof (float));

Could anyone please explain 🙂 ?

Answer 1

In C, this cast is not required. The conversion is indeed implicit.

C11 (n1570), § 6.3.2.3 Pointers

A pointer to void may be converted to or from a pointer to any object type. A pointer to
any object type may be converted to a pointer to void and back again; the result shall
compare equal to the original pointer.

Since it is unecessary, cast malloc return or not is another question (see here).