I have written a code using 2D array of getting random numbers using random() and storing in the array using .But i get below error

Asked Jul 12 '20 at 11:24

Active Jul 12 '20 at 11:24

Viewed 13 times

import java.util.*;
public class Main
{   
public static void main(String[] args) 
    {   
        double[][] numbers=new double[10][];
        Random numGen =new Random();
        for(int pos=0;pos<numbers.length-1;pos++)
            {
            int index=0;
            numbers[pos][index]=Math.abs((100)+numGen.nextInt(100));  
            System.out.printf("The random number stored in [%d][%d] : %9.4f",pos,index,numbers[pos][index]);
            System.out.println();}
    }
}

Error: I get the error in the line" numbers[pos][index]=Math.abs((100)+numGen.nextInt(100));" Exception in thread "main" java.lang.NullPointerException
at Main.main(Main.java:11)

asked Jul 12 '20 at 11:24

Jasmine

Could anyone help me to get the output for the above code.? – Jasmine Jul 12 '20 at 11:26
You need to create the row 1D subarray and assign it to the 2D array within your for loop before trying to use it. – DontKnowMuchBut Getting Better Jul 12 '20 at 11:30
Why are you using a 2D array to begin with? What purpose does the 2nd dimension have as you only appear to be adding one item to the row? – DontKnowMuchBut Getting Better Jul 12 '20 at 11:32
example of how to put the above comment in practice: `numbers[pos]=new double[3];` here 3 is the size of the 1D sub array – Joni Jul 12 '20 at 11:34

I have written a code using 2D array of getting random numbers using random() and storing in the array using .But i get below error

0 Answers0