create a 2d array in java code example

Example 1: Create dynamic 2d array in java

// Create dynamic 2d array in java
import java.util.ArrayList;
import java.util.List;
public class Dynamic2dArray 
{
   public static void main(String[] args) 
   {
      List<int[]> li = new ArrayList<>();
      li.add(new int[]{2,4,6});
      li.add(new int[]{3,5});
      li.add(new int[]{1});
      // element at row 0, column 0
      System.out.println("Element at [0][0]: " + li.get(0)[1]);
      // get element at row : 1, column : 1
      System.out.println("Element at [1][1]: " + li.get(1)[1]);
   }
}

Example 2: 2d array java

//Length
int[][]arr= new int [filas][columnas];
arr.length=filas;

        int[][] a = {
            {1, 2, 3}, 
            {4, 5, 6, 9}, 
            {7}, 
        };
      
        // calculate the length of each row
        System.out.println("Length of row 1: " + a[0].length);
        System.out.println("Length of row 2: " + a[1].length);
        System.out.println("Length of row 3: " + a[2].length);
    }

Example 3: How to create a 2d array in java

int[][] arr = new int[m][n];

Example 4: 2d array java

int[][] arr = new int[10][20]; 
        arr[0][0] = 1;

Example 5: declare matrix in java

int[][] multi = new int[5][];
multi[0] = new int[10];
multi[1] = new int[10];
multi[2] = new int[10];
multi[3] = new int[10];
multi[4] = new int[10];