Question

How to declare dynamic 2D array using new in C++

Answer 1

#include <iostream>
#include <iomanip>

constexpr int ROW = 3;
constexpr int COL = 4;

int main()
{
    int **matrix = new int*[ROW];
    
    for(int i = 0; i < ROW; i++) {
        matrix[i] = new int[COL];
    }

    srand(time(NULL));
    for(int i = 0; i < ROW; ++i) {
        for(int j = 0; j < COL; ++j) {
            matrix[i][j] = rand() % 100;
            std::cout << std::setw(2) << matrix[i][j] << " ";
        }
        std::cout << "\n";
    }

    for(int i = 0; i < ROW; ++i) {
        delete matrix[i];
    }
    delete [] matrix;
 
    return 0;
}
     
     
     
     
/*
run:
   
91 82  1 67 
92  9 23 94 
20 20 12 42 
      
*/

 

70+ SQL courses for beginners and professionals