Correct C pointer notation [closed]

问题

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Closed 9 years ago.

Which one is the best way to write:

string* str

Or:

string *str

Is there any drawback of side effect to one of them ?

Thanks

回答1:

A reason to prefer the second one is when you declare multiple variables at once:

string *str, *foo;
string* str, foo;

Those two lines are different, the first one declares to pointers, whereas the second one declares one pointer to string and one string.

[Comment by FredOverflow] This problem can be solved by some template magic, though ;-)

template <typename T>
struct multiple
{
    typedef T variables;
};

multiple<string*>::variables str, foo;

回答2:

Although I prefer the first one there is a reason to prefer the second, consider:

string* str, a;
string *str, a;

In the last case it is clear that * applies only to str. However using such declarations is often considered a bad style.

回答3:

I do it like this:

string *str;

Because it makes a difference when you do this

string *str, *str2;

You could also do

typedef string* stringPtr;

So that you could do

stringPtr str, str2;

回答4:

In C++ - neither - this should be const string& str.

Or is that const string &str ? Hmm.

来源：https://stackoverflow.com/questions/4071068/correct-c-pointer-notation