1：代码如下：

// 4.1.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include 
      
       using namespace std;void ShowMessage();    //函数声明语句void ShowAge();        //函数声明语句void ShowIndex();        //函数声明语句void main(){    ShowMessage();    //函数调用语句    ShowAge();        //函数调用语句    ShowIndex();        //函数调用语句}void ShowMessage(){    cout << "HelloWorld!" << endl;}void ShowAge(){    int iAge=23;    cout << "age is :" << iAge << endl;}void ShowIndex(){    int iIndex=10;    cout << "Index is :" << iIndex << endl;}
      

运行结果：