这是我在头文件中使用的代码:
#ifndef TETRIS_TETRIMINO
#define TETRIS_TETRIMINO
const int TETRIMINO_GRID_SIZE = 4;
struct Location {
int row;
int col;
};
class Tetrimino {
private:
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE];
char color;
Location location;
public:
// constructor
Tetrimino(int type = 7); // valid type values are 0-6
//---------------------------------------------
//accessors
char getColor();
Location getLocation();
void getGrid(int gridOut[][TETRIMINO_GRID_SIZE]);
//---------------------------------------------
//mutators
void setLocation(Location newLocation);
void setLocation(int row, int col);
void rotateLeft();
void rotateRight();
void moveLeft();
void moveRight();
void moveDown();
void moveUp();
//---------------------------------------------
//others
void dataDump();
};
#endif
这是.cpp:
#include "tetrimino.h"
#include <iostream>
#include <ctime>
using namespace std;
//random number generator
int randNum()
{
int randNum;
int high = 6;
int low = 0;
srand(static_cast<unsigned int>(time(NULL)));
randNum = rand() % (high - low + 1) + low;
return randNum;
}
Tetrimino::Tetrimino(int type)
{
//check to see if type is 0-6, if not set to 7
if (type < 0 || type >= 7)
{
type = randNum();
}
//set associated type to a tetrimino
if (type == 0)
{
//set grid to i tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 1, 1, 1, 1 },
{ 0, 0, 0, 0 },
{ 0, 0, 0, 0 }
};
//set color to teal
color = 't';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 1)
{
//set grid to j tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 1, 0, 0 },
{ 0, 1, 1, 1 },
{ 0, 0, 0, 0 }
};
//set color to blue
color = 'b';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 2)
{
//set grid to L tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 0, 1, 0 },
{ 1, 1, 1, 0 },
{ 0, 0, 0, 0 }
};
//set color to orange
color = 'o';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 3)
{
//set grid to o tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 1, 1, 0 },
{ 0, 1, 1, 0 },
{ 0, 0, 0, 0 }
};
//set color to yellow
color = 'y';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 4)
{
//set grid to s tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 1, 1, 0 },
{ 1, 1, 0, 0 },
{ 0, 0, 0, 0 }
};
//set color to green
color = 'g';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 5)
{
//set grid to T tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 1, 0, 0 },
{ 1, 1, 1, 0 },
{ 0, 0, 0, 0 }
};
//set color to purple
color = 'p';
//initialize starting position
location.row = 0;
location.col = 0;
}
else if (type == 6)
{
//set grid to z tetro
int grid[TETRIMINO_GRID_SIZE][TETRIMINO_GRID_SIZE] =
{
{ 0, 0, 0, 0 },
{ 0, 1, 1, 0 },
{ 0, 0, 1, 1 },
{ 0, 0, 0, 0 }
};
//set color to red
color = 'r';
//initialize starting position
location.row = 0;
location.col = 0;
}
};
//accessors
char Tetrimino::getColor()
{
return color;
}
Location Tetrimino::getLocation()
{
return location;
}
void Tetrimino::getGrid(int gridOut[][TETRIMINO_GRID_SIZE])
{
//loop goes through each row
for (int row = 0; row < TETRIMINO_GRID_SIZE; row++)
{
//goes through each col of current row
for (int column = 0; column < TETRIMINO_GRID_SIZE; column++)
{
cout << gridOut[row][column] << " ";
}
//new line between rows
cout << endl;
}
}
//mutators
//leaving these out of this for sanity
void main()
{
Tetrimino test(0);
cout << test.getColor() << endl;
test.getGrid(test.grid);
}
好的，显然代码不完整。我对如何使用公共(public)函数 getGrid 从 Tetrimino 类打印出网格数组感到非常困惑和困惑。头文件是预先制作好的(虽然我理解)所以我不想编辑它。为什么 getGrid 函数首先需要一个参数？
我不能像在 main() 中尝试的那样简单地调用我想要打印的网格，因为它是私有(private)的。我只是真的..是的，我知道这是错误的，但我不知道如何去做正确的事。
编辑/更新: 我从 getGrid() 中删除了参数，并将函数中的 gridOut 更改为简单的网格。但是，当我使用 test.getGrid() 调用函数时，打印的数组是:
-858993460 -858993460 -858993460 -858993460
-858993460 -858993460 -858993460 -858993460
-858993460 -858993460 -858993460 -858993460
-858993460 -858993460 -858993460 -858993460
我更改的代码是:
void Tetrimino::getGrid()
{
//loop goes through each row
for (int row = 0; row < TETRIMINO_GRID_SIZE; row++)
{
//goes through each col of current row
for (int column = 0; column < TETRIMINO_GRID_SIZE; column++)
{
cout << grid[row][column] << " ";
}
//new line between rows
cout << endl;
}
}
getGrid 已更改为网格。
我现在这样调用函数:
void main()
{
Tetrimino test(0);
test.getGrid();
}
最佳答案
正如您提到的，头文件已提供给您，我猜这是一项作业。 getGrid 方法旨在为外部调用者提供接口(interface)以获取 Tetrmino 对象网格的拷贝。由于您无法从函数返回数组，因此 getGrid 方法提供了一个输出参数。
示例用法:
void Tetrimino::getGrid(int gridOut[][TETRIMINO_GRID_SIZE]) {
for(int i = 0; i < TETRMINO_GRID_SIZE; i++) {
for(int j = 0; j < TETRMINO_GRID_IZE; j++ ) {
gridOut[i][j] = grid[i][j];
}
}
}
...
...
Tetrmino obj(3);
...
...
int grid[TETRIMINO_GRID_SIZE][TETRMINO_GRID_SIZE];
obj.getGrid(grid);
// now grid holds the copy of interal grid
for(int i = 0; i < TETRMINO_GRID_SIZE; i++) {
for(int j = 0; j < TETRMINO_GRID_IZE; j++ ) {
std::cout << grid[i][j] << " ";
}
std::cout << "\n";
}
std::cout << std::flush;
编辑: 扩展答案:为什么没有分配网格？
问题是，在您的构造函数中，您声明了一个与类成员同名的新 int 数组。这意味着，您没有初始化成员变量。 C++ 不允许在初始化后分配给原始数组，您只能进行复制。
将新变量更改为 gridNew 或类似的变量，然后逐个元素地从 gridNew 复制到 grid 就像您现在从 grid 到 getGrid 方法中的 gridOut。
关于C++ 类 : using a private array in a public function?，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28293366/