静态2D数组，添加元素

Question

My problem is in adding elements. If I tried to add again it's just replacing the last add position. where when adding, it supposed to be moving to the next slot/index.

for example

   0  1  2  3  4  5
0| a  b  c  d  e  f
1| g  h  i  j  k  l
2| 

Add element:m

 0  1  2  3  4  5
0| a  b  c  d  e  f
1| g  h  i  j  k  l
2| m  

Add element:n

0  1  2  3  4  5
0| a  b  c  d  e  f
1| g  h  i  j  k  l
2| m  n

here is my code:

  #include<iostream>
    #include<string>

    std::string myarray[3][6] = {{"a","b","c","d","e","f"},
                                {"g","h","i","j","k","l"},
                                {" "," "," "," "," "," "}}; 


    void display();

    using namespace std;

    int main(){

    while(true){

        display();

        char add;
        int rows = 2;
        int cols = 6;

        cout<<"==========================================" <<endl;
        cout<<"Add element: ";
        cin>>add;

        int size = rows*cols;
        myarray[0][size] = add;

        cout<<"Adding Successful!" <<endl;

        size=size+1;
    }

    }

    //display
    void display(){

        cout<<endl;
        for(int z = 0; z<6; z++){
            cout<<"  "<<z;
        }
        cout<<endl;

        for(int x = 0; x<3; x++){
        cout<<x <<"|";
            for(int y = 0; y<6; y++){
                cout<<" " <<myarray[x][y] <<" "; 
            }
        cout<<endl;
        }
    }

Answer 1

Always the element myarray[0][size] is assigned a new value where in each iteration a new int size = rows*cols; is calculated ( size = 12). And your are accessing the Array out of ist limits

Without any of the other issues taking into account this might be fixed:

int col=0;
while (col < 6) {
    display();

    char add;

    cout<<"==========================================" <<endl;
    cout<<"Add element: ";
    cin>>add;

    myarray[2][col] = add;

    cout<<"Adding Successful!" <<endl;

    ++col;
}

Answer 2

The problem is int his part of code

int rows = 2;

    int cols = 6;

cout<<"==========================================" <<endl;
cout<<"Add element: ";
cin>>add;

int size = rows*cols;
myarray[0][size] = add

;

You need something like ++rows or ++cols and call

myarray[rows][cols] = add