Reputation: 4739

Asterisk space in C - What does the additional white space mean?

I think that *something and * something are different.

What does the additional white space do?

occurs here -> void * malloc( size_t number_bytes );

Upvotes: 4

Answers (7)

John Bode

Reputation: 123448

The * operator in a declaration always binds to the declarator; the line

void * malloc (size_t number_bytes);

is parsed as though it had been written

void (*malloc(size_t number_bytes));

It's an accident of C syntax that you can write T *p; or T* p; or even

T             *                     p;

but all of them are parsed as T (*p); -- the whitespace makes no difference in how the declarations are interpreted.

Upvotes: 2

Mark Byers

Reputation: 838096

When you use an asterisk to get the value of an address it is called the dereference operator. For example:

int x = *something;

In the example in your question the asterisk has a different meaning because it is part of a type, not part of an expression. It is used to specify that the return type is a pointer (in your specific example, a void pointer).

The extra space does not mean anything and is ignored by the compiler. It is there only to aid readability.

Upvotes: 10

Justin Ardini

Reputation: 9866

int* foo == int *foo == int * foo == int  *   foo

The whitespace does not make any difference to the compiler.

Upvotes: 13

nmichaels

Reputation: 50943

In your void * malloc(...) example, void * is the type. malloc returns a pointer to void, which is just a pointer that needs to be cast to a particular type in order to be useful.

Upvotes: 0