Java - Variable Size Array

If the column size in the arrays are in zig-zag form means not fixed for every row than variable size array is useful.

Syntax to declare variable size array

int x[][] = new int [3][];
x[0] = new int [2];
x[1] = new int [4];
x[2] = new int [3];

Example 1: Input 3 student marks using variable size array.

package variablesizearray;

import java.util.Scanner;
public class Variablesizearray {
    public static void main(String[] args) {
        int i, j;
        int a[][] = new int [3][];
        a[0] = new int[3];
        a[1] = new int[5];
        a[2] = new int[4];
        
        Scanner scan = new Scanner(System.in);
        for(i=0;i<=2;i++) //row
        {
            System.out.println("Enter " + (i+1) + " student marks");
            for(j=0;j<a[i].length;j++) //col
            {
                a[i][j] = scan.nextInt();
            }
        }

        for(i=0;i<=2;i++)
        {
            System.out.println((i+1) + " student marks is: ");
            for(j=0;j<a[i].length;j++) //col
            {
                System.out.print(a[i][j]);
            }
            System.out.println("\n");
        }
    }
}