C语言函数指针的例子

[code]#include <iostream>

//定义一个类型别名 Fuction：参数为int，返回值为void

typedef void(*Fuction)(int);

void positive(int n)

{

cout <<n <<"is a positive number" << endl;

}

void negative(int n)

{

cout << n<<" is a negative number" << endl;

}

void zero(int n)

{

cout << n << " is zero" << endl;

}

void testCallBack(int n,Fuction *PF)

{

if (n==0)

  {

*PF = zero;

}else if (n > 0)

  {

*PF = positive;

  }

else

  {

*PF = negative;

  }

(*PF)(n);

}

int main()

{

  Fuction  mFuction;      //声明一个函数指针。   

int a = 3;

int b = 0;

testCallBack(a, &mFuction);

testCallBack(b, &mFuction);

return 0;

}