What is a `char*`?

What is a char*, exactly? Is it a pointer? I thought pointers had the ast开发者_如何学运维erisk before the identifier, not the type (which isn't necessarily the same thing)...?

It is a pointer to a char.

When declaring a pointer, the asterisk goes after the type and before the identifier, with whitespace being insignificant. These all declare char pointers:

char *pointer1;
char* pointer2;
char * pointer3;
char*pointer4;    // This is illegible, but legal!

To make things even more confusing, when declaring multiple variables at once, the asterisk only applies to a single identifier (on its right). E.g.:

char* foo, bar;    // foo is a pointer to a char, but bar is just a char

It is primarily for this reason that the asterisk is conventionally placed immediately adjacent to the identifier and not the type, as it avoids this confusing declaration.

It is a pointer to a character. You can write either

char* bla;

or

char *bla;

It is the same.

Now, in C, a pointer to a char was used for strings: The first character of the string would be where the pointer points to, the next character in the address that comes next, etc. etc. until the Null-Terminal-Symbol \0 was reached.

BUT: There is no need to do this in C++ anymore. Use std::string (or similar classes) instead. The char* stuff has been named the single most frequent source for security bugs!

http://cplusplus.com/doc/tutorial/pointers/

The * character shows up in two distinct places when dealing with pointers. First, the type "pointer to T" is denoted by T* (appending * to the type name). Second, when dereferencing a pointer, which is done by prepending * to the name of the pointer variable that you want to dereference.

Whitespace doesn't normally matter, so

char* suchandsuch;

char *suchandsuch;

char
*
suchandsuch;

are all the same.