Error: " expected unqualified-id before 'int' ", array, argument, function,

Question

我是 C++ 的新手，目前正在通过认证学习这门语言。我之前只用过Python.

等语言

我发现了类似的帖子，但 none 可能与我的代码有关。

我有以下代码来创建一个十六进制游戏。我正在尝试有一个简单的功能来在玩家每次移动时显示棋盘。

我一开始尽量保持代码简单（限制使用指针和库）。

我有这个错误： hex_game.cpp:9:47: 错误：在 'int' 之前需要不合格的 id 9 | void display_current_array(数组[大小][大小], 整数大小){ |

下面是我的代码，希望有人能帮忙:


#include <iostream>
#include <stdlib.h>
using namespace std;
#include <vector>
#include <array>


// a void function to display the array after every moove
void display_current_array(array[size][size], int size){

    
    //s=arr.size();
    for (int i = 0; i < size; i++)
    {
        for (int j = 0; j < size; j++)
        {
            cout<<array[i][j]<<endl;
        }
        
    }
    

}

int main(){
    // the HEX game is a game of size cases represented by an array either filled with a color;
    // int size =11; //as asked but we can play on a differnt board
    int size;

    // ask the player to give a board size
    cout << "What is the size of your Hex Board ? ";
    cin>> size;

    // create the array to represent the board
    int array[size][size];




    // the player will choose colors that we will store as an enum type
    enum colors {BLUE, RED};

    
    
    // initialize the array: all positions are 0
    for (int i = 0; i < size; i++)
    {
        for (int j = 0; j < size; j++)
        {
            array[i][j]=0;
        }
        
    }

    display_current_array(array, size);

}

Answer 1

编写此代码的更好方法是使用 STL 向量容器。如果你想用数组来做，你需要了解指针。

#include <iostream>
#include <stdlib.h>
#include <vector>
using namespace std;



// a void function to display the array after every moove
void display_current_array(vector<vector<int>> &array, int size){ // & means pass-by-reference

    
    //s=arr.size();
    for (int i = 0; i < size; i++)
    {
        for (int j = 0; j < size; j++)
        {
            cout << array[i][j] << endl;
        }
        
    }
    

}

int main(){
    // the HEX game is a game of size cases represented by an array either filled with a color;
    // int size =11; //as asked but we can play on a differnt board
    int size;

    // ask the player to give a board size
    cout << "What is the size of your Hex Board ? ";
    cin >> size;

    // create the array to represent the board
    vector<vector<int>> array;


    // the player will choose colors that we will store as an enum type
    enum colors {BLUE, RED};

    
    
    // initialize the array: all positions are 0
    for (int i = 0; i < size; i++)
    {
        vector<int> row;
        for (int j = 0; j < size; j++)
        {
            row.push_back(0);
        }
        array.push_back(row);
        
    }

    display_current_array(array, size);

}

在这里，我使用 & 操作数通过引用传递向量。

void display_current_array(vector<vector<int>> &array, int size)

Answer 2

在标准C++中，数组的大小必须是编译时间常数。所以当你写道：

int size;
cin>> size;
int array[size][size]; //NOT STANDARD C++

声明array[size][size];不是标准的c++。

第二个当你写道：

void display_current_array(array[size][size], int size){
//...
}

请注意，在函数 display_current_array 的第一个参数中，您 未指定数组包含的元素的类型 。所以这将导致您收到错误。

解决方案

避免这些并发症的更好方法是使用动态大小的容器，例如 std::vector，如下所示：

#include <iostream>
#include <vector>

// a void function to display the vector after every moove
void display_current_array(const std::vector<std::vector<int>> &vec){//note the vector is passed by reference to avoid copying
  
    for(auto &row: vec)
    {
        for(auto &col: row)
        {
            std::cout << col ;
        }
        std::cout<<std::endl;
    }
}

int main(){
    int size;

    // ask the player to give a board size
    std::cout << "What is the size of your Hex Board ? ";
    std::cin>> size;

    // create the 2D STD::VECTOR with size rows and size columns to represent the board
    std::vector<std::vector<int>> vec(size, std::vector<int>(size));

    // the player will choose colors that we will store as an enum type
    enum colors {BLUE, RED};

    //NO NEED TO INITIALIZE EACH INDIVIDUAL CELL IN THE 2D VECTOR SINCE THEY ARE ALREADY INITIALIED TO 0

    display_current_array(vec);

}

注意：

我们不需要将向量的大小作为参数传递
矢量通过引用传递以避免复制

上面程序的输出可见here.

Error: " expected unqualified-id before 'int' ", array, argument, function,

Error: " expected unqualified-id before 'int' ", array, argument, function,

c++

arrays

void

display

解决方案