Java is asking me to create a method I have already created

Question

i am trying to call a method to generate a random number, but Java won't let me. It is telling me to create a method even though i already have. Here is my code.

package hw3;

import java.util.Random;

//Zephram Foster, Homework 3, 10-12

public class randomLottery {

    int num[];
    int ball;
    int high;


    public static int generateRandomInt(int upperRange){

        Random random = new Random();
        return random.nextInt(upperRange);
    }

}


package hw3;
import java.util.Scanner;
public class randomMain {

    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter the high number: ");
        //int high = sc.nextInt();
        //System.out.println(high);

        randomLottery rand = new randomLottery();
        rand.high = sc.nextInt();
        System.out.println(rand.high);

        rand.num[1] = generateRandomInt(rand.high);
    }

}

the problem is in the main class, the last line. Please help my dudes

@RobbyCornelissen You mean `randomLottery.generateRandomInt(rand.high);`. — shmosel, Oct 16 '18 at 01:07
@shmosel Didn't notice the `static`, but still: either should work. — Robby Cornelissen, Oct 16 '18 at 01:08

Tim Biegeleisen · Answer 1 · 2018-10-16T01:20:03.843

3

The generateRandomInt() method is in another class. Given that this method also happens to be static, you may refer to it as:

rand.num = new int[2];
rand.num[1] = randomLottery.generateRandomInt(rand.high);

Note that Java naming conventions say that class names should begin with a capital letter, so call the other class RandomLottery.

I don't know what the rest of your not yet written code would look like. Java arrays begin an index zero, so the following assignment might make more sense:

rand.num[0] = randomLottery.generateRandomInt(rand.high);

edited Oct 16 '18 at 01:20

answered Oct 16 '18 at 01:07

Tim Biegeleisen

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or import static? – Scary Wombat Oct 16 '18 at 01:08
Thanks, that gets rid of the red underline, but it still wont run. Now when i run it with that change it tells me:Exception in thread "main" java.lang.NullPointerException at hw3.randomMain.main(randomMain.java:16) – Zephram Foster Oct 16 '18 at 01:09
You need to intialize the `int[]` array. – Tim Biegeleisen Oct 16 '18 at 01:10
1

I wonder why `num` etc variables are in the `randomLottery` class. – Scary Wombat Oct 16 '18 at 01:11
1

Also Arrays in Java start at index `0` – Scary Wombat Oct 16 '18 at 01:12
@ScaryWombat If you see a can with a worm crawling out of it, and then you open it, what do you get? You get a can of worms. – Tim Biegeleisen Oct 16 '18 at 01:13
yes, I'll fix and have it start at 0. should the variable be somewhere else? I am new to java. – Zephram Foster Oct 16 '18 at 01:14
@TimBiegeleisen Sorry, Tim the comments were not aimed at you. You still got my upvote – Scary Wombat Oct 16 '18 at 01:16

Java is asking me to create a method I have already created

1 Answers1