訪問C++中的.h文件中的類

Question

你好我是在我的程序中使用頭文件和OPP的新手段，我想知道爲什麼Visual Studio 2010會說我的代碼中有錯誤。該代碼可以編譯和運行根據需要，但也有下的所有對象

的紅線這裏是頭文件

//functions.h 
#include "stdafx.h" 
#include <iostream> 
#include <ctime> 
#include <string> 

using namespace std; 

class vehicle 
{ 
public: 
int hp; 
int ammo; 
void displayHP(); 
void displayAmmo(); 
void displayName(); 
string vesselName; 
void setName(string); 
void moveUP(int& y); 
void moveDown(int& y); 
void moveLeft(int &x); 
void moveRight(int &x); 
private: 
}; 
//implementation section 
void vehicle::displayHP(){cout<<hp<<endl;} 
void vehicle::displayAmmo(){cout<<ammo<<endl;} 
void vehicle::setName(string name){vesselName=name;} 
void vehicle::displayName(){cout<<vesselName<<endl;} 
void vehicle::moveUP(int& y) 
    { 
     y=y-1;//moves boat up 
     system("cls"); 
    } 
void vehicle::moveDown(int& y) 
{ 
     y=y+1;//moves boat down 
     system("cls"); 
} 
void vehicle::moveLeft(int &x) 
{ 
     x=x-1;// moves the boat left 
     system("cls");  
} 


void vehicle::moveRight(int &x) 
{ 
    x=x+1;//moves boat right 
    system("cls"); 
} 
void moveBoat(int &x,int& y, int a,int b,int s,int turn) 
{ 

這裏是包含船運動的頭文件。該程序編譯細而設計的，但我很困惑，爲什麼Visual Studio是聲稱有這麼多的錯誤，我添加的行評價，其中在boat.h文件

//boat.h 
#include "stdafx.h" 
#include <iostream> 
#include <ctime> 
#include <string> 
#include "functions.h" 

using namespace std; 

void moveBoat(int &x,int& y, int,int,int,int); 
void youScrewedUp(int &x,int& y, int,int,int,int); 



int movement=0; 

vehicle destroyer; 
    destroyer.hp=500;//<==== getting a red line under the word destroyer error says "this deceleration has no storage class or type specifier" 
    destroyer.ammo=500;//<==== getting a red line under the word destroyer error says "this deceleration has no storage class or type specifier" 



displayArray(x,y,a,b,s);//<===="this deceleration has no storage class or type specifer" 
destroyer.setName("USS YAY I LEARNED CLASSES");//<===="this deceleration has no storage class or type specifer" 
destroyer.displayName();//<===="this deceleration has no storage class or type specifer" 
destroyer.displayHP();//<===="this deceleration has no storage class or type specifer" 
cout<<"Boat Location X "<<x<<" Y "<<y<<endl; 
if(s==1) 
{ 
cout<<"ENEMY SHIP SIGHTED"<<endl;//<===="this deceleration has no storage class or type specifer" 
} 
cout<<"1.move left"<<endl;//<===="this deceleration has no storage class or type specifer" 
cout<<"2.move right"<<endl;//<===="this deceleration has no storage class or type specifer" 
cout<<"3.move up"<<endl;//<===="this deceleration has no storage class or type specifer" 
cout<<"4.move down"<<endl;//<===="this deceleration has no storage class or type specifer" 
cin>>movement;<===="this deceleration has no storage class or type specifer" 

    switch(movement)//<==expected a deceleration 
    { 
    case 1: 
     if(x>0)//does not allow boat to leave grid 
     { 
      destroyer.moveLeft(x); 
     } 
     else 
     { 
      youScrewedUp(x,y,turn,a,b,s);// function that repeats the movement function and displays a message 
     } 
     break; 

     case 2: 
     if(x<9)//boundary 
     { 
      destroyer.moveRight(x); 
     } 
     else 
      { 
      youScrewedUp(x,y,turn,a,b,s); 
      } 
     break; 

     case 3: 
     if(y>0)//boundary 
     { 
      destroyer.moveUP(y); 
     } 
     else 
      { 
      youScrewedUp(x,y,turn,a,b,s); 
      } 
     break; 

     case 4: 
     if(y<9)//boundary 
     { 
      destroyer.moveDown(y); 
     } 
     else 
      { 
      youScrewedUp(x,y,turn,a,b,s); 
      } 
     break; 


    } 
    turn++;//adds one to the turn counter to cycle to the enemies turn 



} 

void youScrewedUp(int &x, int &y,int turn, int a, int b,int s)// must pass the x y values by refferance 
{ 
cout<<"where are you going your leaving the battlefield"<<endl; 
      cout<<"please make another selection"<<endl; 
      system("pause"); 
      system("cls"); 
      moveBoat(x,y,turn,a,b,s); 
} 

這裏的錯誤是我的主要工作（）

// arrayTest.cpp : Defines the entry point for the console application. 
// 

#include "stdafx.h" 
#include "array.h" 
#include "boat.h" 
#include "enemy.h" 
#include <iostream> 
#include <ctime> 

using namespace std; 

int main() 
{ 
int turn=1;// turn counter cycles between 1 and 2 during player and enemy turns 
int x=7;//x coordinate for destroyer 
int y=6;//y coordinate for destroyer    
int a=3;//x coordinate for sub 
int b=4;//y coordinate for sub 
int s=0;//toggle for submerged or not chose not to use a bool because I used a random number generator to allow a 25% chance opposed to a 50% chance 
srand (time(NULL)); 

do{ 
    moveBoat(x,y,turn,a,b,s);//function that moves the boat 
    moveEnemy(a,b,turn,x,y,s);//function to move the enemy 
}while(turn<3);// this is temporary will be replaced when a hp and weapons system is completed 
    system("pause"); 
return 0; 
} 

Answer 1

這超出了您的基本問題，並添加了一些其他的東西，這些東西將改善您的代碼並希望能夠理解。

1. 你需要從字面上把你的「主」的功能代碼在主函數

   int main(int argc, char * argv[]) 
   { 
       //do stuff here.... 
       return 0; 
   } 
   

2. 你應該包括頭部防護，以防止你包括「function.h」多次。我也強烈建議將它重命名爲Vehicle.h，以表示它正在提供的類。

   #ifndef __VEHICLE_H__ 
   #define __VEHICLE_H__ 
   //... all the good stuff. 
   
   #endif 
   

3. 我強烈建議你從你的頭文件中刪除using namespace std，因爲這樣做將垃圾人誰願意使用你的頭的命名空間。在需要的地方簡單地使用std::，或者如果您不想在任何地方使用它們，請考慮爲您正在使用的特定功能執行using std::xyz;。這種方式至少可以在以後追溯碰撞。如果你想在一個實現文件（即*.c）中這樣做，但不要在通常包含的文件中進行。

4. 請勿在頭文件中包含您未使用的頭文件。這是一個壞習慣，導致代碼和編譯器膨脹，並且不可避免地會導致以後的痛苦。您不應在每個標題中包含ctime或stdafx，因爲它們不會引用它。

5. 你需要把身體的「東西」是浮動的內部boat.h成函數

   //somefunct 
   void somefunction() 
   { 
       int movement=0; 
   
       vehicle destroyer; 
       destroyer.hp=500;//<==== getting a red line under the word destroyer error says "this deceleration has no storage class or type specifier" 
       destroyer.ammo=500;//<==== getting a red line under the word destroyer error says "this deceleration has no storage class or type specifier" 
   
   
       //.... Everything else 
   
   }