example1.cpp
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#include <iostream>
using namespace std;
int main(){
        int numbers[4][3]={{1,2,3},{4,5,6},{7,8,9},{10,11,12}};
        int i, j;
        for(i=0;i<4;i++){
                for(j=0;j<3;j++)
                        cout << numbers[i][j] << "\t";      
                cout << endl;
        }
        return 0;
}

===============================================

example2.cpp
-----------------------------------------------
#include <iostream>
using namespace std;
int main(){
        int numbers[4][3]={{1,2,3},{4,5,6},{7,8,9},{10,11,12}};
        int i,j,row,column,n;
        while(1){
            for(i=0;i<4;i++){       // print array
                for(j=0;j<3;j++)
                    cout << numbers[i][j] << "\t";
                cout << endl;
            }
            do{             // enter row number
                cout << "Enter row number: ";
                cin >> row;
            }while(row>3||row<0);
            do{             // enter column number
                cout << "Enter column number: ";
                cin >> column;
            }while(column<0||column>2);
            cout << "Enter new value: ";    // enter new value
            cin >> n;
            numbers[row][column]=n;       // reset value
        }
        return 0;
}

================================================

example3.c
------------------------------------------------
#include <iostream>
using namespace std;

int main(){

        int numbers[3][3];
        int i,j;
        for(i=0;i<3;i++){
                cout << "Enter values in row " << i << ":" ;
                for(j=0;j<3;j++)
                        cin >> numbers[i][j];
        }
        cout << "The values in the array are: " << endl;
        for(i=0;i<3;i++){
                for(j=0;j<3;j++)
                        cout << numbers[i][j];
                cout << "\n";
        }
        return 0;
}

================================================