I knew this meaning (int *p).But I want this meaning (int *)

[sathi468]

(int *p)means pointer variable of p in integer datatype

[Nepomuk]

Can you give us an example? One case where (int *) may appear would be something like this:

void * pointer = ...;
int * p = (int *) pointer;

Here you are casting the void pointer pointer to an int pointer.

[Banfa]

If you mean a function declaration

void func1(int *p); // 1
void func2(int *);  // 2

Then they both mean exactly the same thing, declare a function that takes 1 int pointer parameter. In a function declarations the parameter names (p in this case) are ignored.

If you mean a function definition

void func1(int *p) // 3
{
  // some code here
  *p = 5;
}

void func2(int *)  // 4
{
  // some code here
}

Then the both still mean the same thing, a function that takes 1 parameter with type pointer to int, however in case 4 you are also declaring that although the function takes a pointer to int parameter it is not used by the functions implementation. A construct sometimes used when you have to create a callback function to a third party API and have no use for the passed data.