How to return 2D array from a method in java?

[itiger]

I wrote sample code to test but it gives error. Following is the code that i wrote:

class ArrCreate
{
    public int[][] createArray()
    {
        int[][] s = new int[3][];
        s[0] = new int[4];
        s[1] = new int[2];
        for(int i = 0; i < s.length; i++)
        {
            for(int j=0; j < s[i].length; j++)
            {
                s[i][j] = j + 1;
            }
        }    
        return s;
    }
    public void displayArray()
    {
        int[][] a;
        a = createArray();
        for(int i = 0; i < a.length; i++)
        {
            for(int j=0; j < a[i].length; j++)
            {
                System.out.println(a[i][j]);
            }
            System.out.println();
        }
 
    }
}
 
class MultiArray
{
    public static void main(String args[])
    {
        ArrCreate Arr = new ArrCreate();
        Arr.displayArray();
    }
}
 

The program gives following error:
Exception in thread "main" java.lang.NullPointerException
at ArrCreate.createArray(MultiArray.java:10…
at ArrCreate.displayArray(MultiArray.java:2…
at MultiArray.main(MultiArray.java:37)

[horace1]

you define s with 3 elements s[3] but only created s[0] and s[1]

        int[][] s = new int[3][];
        s[0] = new int[4];
        s[1] = new int[2];
        s[2] = new int[2];    // << missing??
 

[itiger]

Thank you, it is working now.