Question

#include <iostream>
using namespace std;

int main (){

    int row, 
        column = 0,
        colCount = 3,
        rowCount = 3;

    //for loop
    for (column; column < colCount; column++){

        for(row = 0; row <= (rowCount - 1); row++){

            cout << column << " " << row;

            if(row < (rowCount - 1)){
                cout << ", ";           
            }

        }

        cout << endl;

    }

    //while loop
    while(column < colCount){

        while(row < rowCount){

            cout << column << " "<< row;

            if(row < (rowCount - 1)){
                cout << ", ";           
            }

            row++;          

        }

        cout << endl;   
        column += 1;
        row = 0;
    }

    //do while loop
    do{
        do{
            cout << column << " "<< row;

            if(row < (rowCount - 1)){
                cout << ", ";           
            }

            row++;  
        }while(row < rowCount);

        cout << endl;
        column +=1;
        row = 0;
    }while(column < colCount);

}

当评论出2/3循环时，每个循环都会产生想要的输出。它们似乎在一起运行，并增加了额外的输出。

当前输出：

0 0, 0 1, 0 2
1 0, 1 1, 1 2
2 0, 2 1, 2 2
3 3

通缉输出：

0 0, 0 1, 0 2
1 0, 1 1, 1 2
2 0, 2 1, 2 2

0 0, 0 1, 0 2
1 0, 1 1, 1 2
2 0, 2 1, 2 2

0 0, 0 1, 0 2
1 0, 1 1, 1 2
2 0, 2 1, 2 2

如何从每个循环中获得输出？

Answer 1

您可以按原样保留for循环：

    for (; column < colCount; column++){
        for(row = 0; row <= (rowCount - 1); row++){
            std::cout << column << " " << row;
            if(row < (rowCount - 1))
                std::cout << ", ";
        }
        std::cout << std::endl;
    }

现在column和row在for-loop上方获得3，这使得while loop永远不会被执行。因此，您需要将它们都设为0。

并且，第三个do-while循环总是在任何条件检查之前执行，这就是为什么你得到3 3

无论如何，这是解决问题的方法。

#include <iostream>

int main ()
{
    int row, column = 0, colCount = 3, rowCount = 3;

    //for loop
    for (column; column < colCount; column++){
        for(row = 0; row <= (rowCount - 1); row++){
            std::cout << column << " " << row;
            if(row < (rowCount - 1))
                std::cout << ", ";
        }
        std::cout << std::endl;
    }
    std::cout<<std::endl;
    //while loop
    column = 0;
    row = 0;
    while(column < rowCount){
        while(row < rowCount){
            std::cout << column << " "<< row;
            if(row < (rowCount - 1))
                std::cout << ", ";
            row++;          
        }
        std::cout << std::endl;   
        column += 1;
        row = 0;
    }
    //do while loop
    std::cout<<std::endl;
    column = 0;
    row = 0;
    do{
        do{
            std::cout << column << " "<< row;
            if(row < (rowCount - 1))
                std::cout << ", ";
            row++;  
        }while(row < rowCount);
        std::cout << std::endl;
        column +=1;
        row = 0;
    }while(column < colCount);
    return 0;
}

Answer 2

1）您应该在每个循环开始时将column初始化为0 2）在while和do循环内，在进入内循环之前将row初始化为0

最后的输出3 3是由do-while循环中的单个入口引起的。

需要3个独立的输出

当前输出：

通缉输出：

2 个答案: