| description | title | ms.date | f1_keywords | helpviewer_keywords | ms.assetid | ||||
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Learn more about: void (C++) | void (C++) | 12/13/2022 |
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| d203edba-38e6-4056-8b89-011437351057 |
When used as a function return type, the void keyword specifies that the function doesn't return a value. When used for a function's parameter list, void specifies that the function takes no parameters. When used in the declaration of a pointer, void specifies that the pointer is "universal."
If a pointer's type is void*, the pointer can point to any variable that's not declared with the const or volatile keyword. A void* pointer can't be dereferenced unless it's cast to another type. A void* pointer can be converted into any other type of data pointer.
In C++, a void pointer can point to a free function (a function that's not a member of a class), or to a static member function, but not to a non-static member function.
You can't declare a variable of type void.
As a matter of style, the C++ Core Guidelines recommend you don't use void to specify an empty formal parameter list. For more information, see C++ Core Guidelines NL.25: Don't use void as an argument type.
// void.cppvoidreturn_nothing() { // A void function can have a return with no argument,// or no return statement. } void vobject; // C2182void *pv; // okayint *pint; int i; intmain() { pv = &i; // Cast is optional in C, required in C++ pint = (int *)pv; }