3

What I need to do is make a number generator that stops when it generates 10 and shows how many attempts there was until 10 was reached. I also have to use only while loops for this. Here's my code now:

public static int RandomOccurrence()
{               
  int randNumber = (int)(Math.random()*20 + 1);
  int count = 0;

  while(randNumber != 11){
    System.out.println("The number generated is " + randNumber);
    count = count + 1;
  }
  return count;
}

and here's the function call:

int number = RandomOccurrence();
    System.out.println("It took " +number +" tries before 10 was generated");   
        
    System.out.println();
    System.out.println();

But when I run the code it prints "the number generated is 2" infinitely.

Tyler P
  • 137
  • 9
  • 1
    Take a second look at your while loop. What needs to happen before the while loop will exit? What are you not doing inside that while loop that would allow the exit clause to be met? – scrappedcola Nov 03 '20 at 23:01
  • 1
    Its Tyler again, hello. [Debugging](https://stackoverflow.com/questions/25385173/what-is-a-debugger-and-how-can-it-help-me-diagnose-problems) the thing will be of tremendous benefit, I guess. – Curiosa Globunznik Nov 03 '20 at 23:05
  • 1
    ...what's going to cause `randNumber` to become 11 while you're looping? – CryptoFool Nov 03 '20 at 23:09
  • Why do you loop until ``randNumber = 11``? You're looking for 10, not 11. – NomadMaker Nov 03 '20 at 23:55
  • @nomad I was just trying to see what worked or not. In hindsight, it was a bit dumb lol. – Tyler P Nov 03 '20 at 23:57

4 Answers4

5

Here's a fixed version of your code, which mostly involves moving the line that gets a random number into the while loop:

public static int RandomOccurrence()
{
    int randNumber = 0;
    int count = 0;

    while(randNumber != 10){//I changed the 11 to 10 because you said you wanted to stop at 10
        randNumber = (int)(Math.random()*20 + 1);//added
        System.out.println("The number generated is " + randNumber);
        count = count + 1;
    }
    return count;
}

System.out.println(RandomOccurrence());

Sample result:

The number generated is 1
The number generated is 4
The number generated is 20
The number generated is 19
The number generated is 10
5
CryptoFool
  • 21,719
  • 5
  • 26
  • 44
3

I really prefer to point the user towards the answers for homework problems instead of giving them code that works. Because we're trying to "teach a man to fish."

The problem with the original code is that it must generate another random number within the while loop. The simplest way to do this is to copy-and-paste the same function-call that you used to generate the first one.

P.S.: You'll very quickly now see that "there's more than one way to do it!"

Mike Robinson
  • 8,490
  • 5
  • 28
  • 41
1

you should update your random number every time the while loop gets executed: So randNumber = (int)(Math.random()*20 + 1); should be inside the loop

public static int RandomOccurrence(){               
    int count = 0;
    int randNumber = 0;

    while(randNumber != 11){
        randNumber = (int)(Math.random()*20 + 1);
        System.out.println("The number generated is " + randNumber);
        count = count + 1;
    }
    return count;
}

public static void main(String...args){
    int number = RandomOccurrence();
    System.out.println("It took " +number +" tries before 10 was generated");   
        
    System.out.println();
    System.out.println();
}

I hope I could help

JacktheMouse
  • 25
  • 5
0

Here's a 1-liner:

long count = IntStream.generate(() -> (int)(Math.random() * 20 + 1))
    .takeWhile(i -> i != 11).count();

See live demo.

Bohemian
  • 412,405
  • 93
  • 575
  • 722