在C和C++中，’void*’有什么区别

在学习C和C++编程语言中void函数的区别因素之前，让我们来看一些示例，并深入理解void函数在何处使用，我们可以从中得出什么用例等。

void函数的名字如其所示，在编程中没有任何实体。当调用void函数时，它不会返回任何内容给主要位置；在允许的操作完成后，控制权跳转到调用该过程的地方，这可以是计算、递归或打印任何内容到显示屏幕，然后我们将研究指针的作用并且检查’void*’在C和C++中有什么区别。

C++ void函数-1

// C++ code to demonstrate void()
// returning void()
// here we are writing down the C++ programming language to demonstrate the
// concept of C++ code to demonstrate void() and returning the function
// void() function as well
#include 
using namespace std;

// the below small code snippet demonstrates the void function. It's the syntax
void work()
{
    cout << "As we are expecting it to perform the void function has returned the void to the main control";
}

// Driver void() returning void work()
// this below line (driver void code) returns the 
//void function to the function call from where it has been called in the code
void test()
{
    // this below line returns the void function to the function call 
    // from where it has been called
    return work();
}

// the main driver code functionality starts from here 
int main()
{
    // this below line simple calls the void function, which we have 
    // created just above our int main() function
    test();
    return 0;
}

C++ void函数-2

// C++ code to demonstrate void()
// returning void()
// here we are writing down the C++ programming language to demonstrate the
// concept of C++ code to demonstrate void() and returning the function
// void() function as well
#include 
using namespace std;

// the below small code snippet demonstrates the void function. It's the syntax
void test()
{
    // we are writing the C code display text from here
    cout << "As we are expecting it to perform the void function has returned the void to the main control";

    // this below line returns the void function to the function call 
    // from where it has been called
    return (void)"Nope, it doesn't print anything!";
}

// the main driver code functionality starts from here 
int main()
{
    // this below line simple calls the void function, which we have 
    // created just above our int main() function
    test();
    return 0;
}

输出：

//output_is_for_both_C++_codes_written_above
As we expect it to perform, the void function has returned the void to the central control.

C 空类型函数

// C code to demonstrate void()
// returning void()
// here we are writing down the C programming language to demonstrate the
// concept of C code to demonstrate void() and returning the function
// void() function as well
#include 
 void display_function(void); 
 // the main driver code functionality starts from here 
void main() { 
    // this below line simple calls the void function, which we have 
    // created just above our int main() function
 display_function(); 
} //end of the void main function 
void display_function() { // Definition of Display 
 printf("C void function print statement 1"); 
 printf("C void function print statement 1 perfection in programming in C.\"\n"); 
}

输出：

C void function print statement 1C void function print statement 1 perfection in programming in C."

‘void*’ 在C和C++中有什么不同

在C编程语言中，允许将void*指针分配给任何指针类型，而不需要转换，但C++不允许。我们必须在C++中显式地对void*指针进行类型转换。

让我们看一下下面的示例；以下在C中是有效的，但在C++中不是：

void* pointer;
int *i = pointer; // this is an example of the Implicit conversion from void* to int*

同样地，

int *j = malloc(sizeof(int) * 5);  // this is an example of the Implicit conversion from void* to int*

要使上面的代码在C++中编译通过，我们必须使用显式转换，如下所示，

void* pointer;
int *i = (int *) pointer;
int *j = (int *) malloc(sizeof(int) * 5);