void declarator

When used as a function return type, the void keyword specifies that the function does not 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 is not declared with the const or volatile keyword. A void pointer cannot be dereferenced unless it is cast to another type. A void pointer can be converted into any other type of data pointer.

A void pointer can point to a function, but not to a class member in C++.

You cannot declare a variable of type void.

void 只能声明指针 而且不能声明数组
void *a 中*a不能被引用

但是从这个程序中看：

void fn(void y);
void fo() ;

main()
{
void *a ; //void a;语法错误
int l ;

printf("%d\n", a) ; //printf("%d\n", *a) ;语法错误
}

void fn(void y)
{
return 0 ;
}

void fo()
{

}

这个程序编译没问题
但是其中函数fn却无法调用
fn(*a); fn(a); fn(l); fn(fo()); 都有语法错误

上面是WIN-TC中的编译结果

下面是C-FREE中的编译成功的程序
#include <stdio.h>

void fn(void *y); // void fn(void y);语法错误
void fo() ;

main()
{
void *a ;
int l ;

printf("%d\n", a) ;
fn(a) ; //其他的写法也是语法错误
}

void fn(void *y) //void fn(void y)语法错误
{
//return 0;语法错误
}

void fo()
{

}

这也算TC的一个BUG了吧

以前没仔细研究过
但是现在还是不太清楚它是在内存中是怎么储存的