int MyInt(56);
std::cout<<"MyInt="<<MyInt<<std::endl;
int MySecondInt = int(); //int变量可以这样初始化
std::cout<<MySecondInt<<std::endl;
//那么可不可以这样初始化呢?
int MyThirdInt(int()); //error!!! now, this is exactly a function
所以 MyThirdInt 正确的写法是
int MyThirdInt(int())
{
// other code...
return 0;
}
既然MyThirdInt 是一个函数, 那么里面的参数是什么东东呢?
//我们在声明一个函数
int OtherInt()
{
return 33;
}
//再看三行代码
int (*pfunc)();
pfunc = OtherInt;
std::cout<<"MyThirdInt is: "<<MyThirdInt(pfunc)<<std::endl;
MyThirdInt 的参数是个函数指针,但是函数指针好像不能取出来....
所以这个特殊的Int变量需要重新定义,就像下面这样:
int MyThirdInt(int (*pInt)())
{
return pInt();
}
======================完整代码========================
// hellomsg.cpp :
//
#include "stdafx.h"
#include <iostream>
int OtherInt()
{
return 33;
}
int MyThirdInt(int (*pInt)())
{
return pInt();
}
int _tmain(int argc, _TCHAR* argv[])
{
int MyInt(56);
std::cout<<"MyInt="<<MyInt<<std::endl;
int MySecondInt = int();
std::cout<<MySecondInt<<std::endl;
int (*pfunc)();
pfunc = OtherInt;
std::cout<<"MyThirdInt is: "<<MyThirdInt(pfunc)<<std::endl;
return 0;
}
