Correct way of declaring pointer variables in C/C++

keeda picture keeda · Aug 9, 2011 · Viewed 63.2k times · Source

I noticed some people use the following notation for declaring pointer variables.

(a) char* p;

instead of

(b) char *p;

I use (b). What is the rational behind the notation (a)? Notation (b) makes more sense to me because character pointer is not a type itself. Instead the type is character and the variable may be a pointer to the character.

char* c;

This looks like there is a type char* and the variable c is of that type. But in fact the type is char and *c (the memory location pointed by c) is of that type (char). If you declare multiple variables at once this distinction becomes obvious.

char* c, *d;

This looks weird. Both c and d are same kind of pointers that point to a character. In this since the next one looks more natural.

char *c, *d;

Thanks.

Answer

BlackJack picture BlackJack · Aug 9, 2011

Bjarne Stroustrup said:

The choice between "int* p;" and "int *p;" is not about right and wrong, but about style and emphasis. C emphasized expressions; declarations were often considered little more than a necessary evil. C++, on the other hand, has a heavy emphasis on types.

A "typical C programmer" writes "int *p;" and explains it "*p is what is the int" emphasizing syntax, and may point to the C (and C++) declaration grammar to argue for the correctness of the style. Indeed, the * binds to the name p in the grammar.

A "typical C++ programmer" writes "int* p;" and explains it "p is a pointer to an int" emphasizing type. Indeed the type of p is int*. I clearly prefer that emphasis and see it as important for using the more advanced parts of C++ well.

Source: http://www.stroustrup.com/bs_faq2.html#whitespace

I'd recommend the latter style because in the situation where you are declaring multiple pointers in a single line (your 4th example), having the asterisk with the variable will be what you're used to.