Examples of C + + function pointers and callback functions

This article mainly introduces C + + function pointers and callback function examples, need friends can refer to the following

1. Function pointer

function pointer is a pointer, just this pointer it is not like a normal pointer to be a variable, at this point it is pointing to a function, that is, it stores the address of a function, if we change its value, let it point to the address from point Funa to Point Funb, Then the function of the pointer changes.

2. Callback function

What is a callback function? The callback function is actually a function called by the function pointer! If you pass a pointer to a function as a parameter to a B function, and then the pointer in B functions through a function, call a function, this is the callback mechanism. The B function is the callback function.

3. Use of function pointers

3.1 Function Pointer Declaration

typedef return Type (* function pointer type name) (functional parameter list);

The code is as follows:

#include

using namespace Std;

typedef void (*fun) (int,int); Defining function pointer types

void min (int a,int b);

void Max (int a,int b);

void min (int a,int b)

{int Minvalue=a

std::cout<< "min value is" <

}

void Max (int a,int b)

{int maxvalue=a>b?a:b;

std::cout<< "Max value is" <

}

int main ()

{Fun pfun=null;//define function pointer variable Pfun

Pfun=min; Both of the assignment methods are supported

pfun=&min;

Pfun (1,2); This gets the minimum value

Pfun=max;

pfun=&max;

Pfun (1,2); Get maximum value here

return 0;

}

Note : Please pay attention to the triple programming Tutorials section for more wonderful articles .