Print all numbers in between a set value in an array

Question

Im wondering how to print all numbers inbetween a set value in an array with random numbers. It should also state how many of the users random numbers are above the set value. Here is an example of how it could look:

"How many random numbers between 0 – 999 do you want? 12

These are your numbers

998 168 859 32 533 390 339 243 328 164 536 375

these 8 numbers is between 0 – 499

168 32 390 339 243 328 164 375

these 4 numbers is between 500 – 999

998 859 533 536"

this is my code so far, i have managed to get it to print the largest number.

public static void main(String[] args)
{
    Scanner in = new Scanner(System.in);                                                    
    System.out.print(" How many random numbers between 0 – 999 do you want? ");     
    int varde = in.nextInt();   
    System.out.println(" ");
    System.out.println(" this is your numbers:");

    int randomArray[]=new int[varde]; 

    for(int i = 0; i<varde; i++)
    {   
        randomArray [i] = (int) (Math.random () * 999); 
        System.out.println(randomArray[i]);
    }

    int largest = randomArray[0]; 
    for(int x=0; x<randomArray.length; x++){ 
        if(randomArray[x]>largest){ 
            largest =  randomArray[x]; 
        } 
    } 

    System.out.print("Largest no is: "+largest); 
}

Answer 1

There you go.

What i did was add the java.util.Random class instead of Math.random() for random number generation.

Used an ArrayList that allocates more memory if it needs more, to store the values that are lower or greater than 499.

public static void main(String[] args)
{
    Scanner in = new Scanner(System.in);                                                    
    System.out.print(" How many random numbers between 0 – 999 do you want? "); 
    int varde = in.nextInt();   
    System.out.println(" ");
    System.out.println(" this is your numbers:");
    Random randomGenerator = new Random();

    int randomArray[]=new int[varde];

    for(int i = 0; i<varde; i++)
    {   
        randomArray[i] = randomGenerator.nextInt(1000); 
        System.out.print(randomArray[i]);
    }

    int largest = randomArray[0]; 
    for(int x=0; x<randomArray.length; x++){ 
        if(randomArray[x]>largest)
            largest =  randomArray[x]; 
    }
    System.out.println("Largest no is: "+largest); 

    List<Integer> numbersGreaterThanHalf = new ArrayList<Integer>();
    List<Integer> numbersLowerThanHalf = new ArrayList<Integer>();

    for(int x=0; x<randomArray.length; x++){ 
        if(randomArray[x]>499) 
            numbersGreaterThanHalf.add(randomArray[x]);
        else
            numbersLowerThanHalf.add(randomArray[x]);
    }

    System.out.println("these " + numbersLowerThanHalf.length() + "numbers is between 0 – 499");
    for(Integer number: numbersLowerThanHalf)
    {
       System.out.print(number + " ");
    }

    System.out.println("these " + numbersGreaterThanHalf.length() + "numbers is between 500 – 999");
    for(Integer number: numbersGreaterThanHalf)
    {
       System.out.print(number + " ");
    }
}

No new arrays implementation extract:

  StringBuilder numbersAboveHalf = new StringBuilder();
  StringBuilder numberBelowHalf = new StringBuilder();
  int countOfNumbersAboveHalf = 0;
  int countOfNumbersBelowHalf = 0;

  for(int x=0; x<randomArray.length; x++){ 
        if(randomArray[x]>499){
            numbersAboveHalf.append(randomArray[x]).append(" ");
            ++countOfNumbersAboveHalf;
        }
        else{
            numbersBelowHalf.append(randomArray[x]).append(" ");
            ++countOfNumbersBelowHalf;
        }
  }
  System.out.println("these " + countOfNumbersBelowHalf + "numbers is between 0 – 499");
  System.out.println(numbersBelowHalf.toString());
  System.out.println("these " + countOfNumbersAboveHalf + "numbers is between 500 – 999");
  System.out.println(numbersAboveHalf.toString());

What this does is iterate over the array and:

• count how many number above 500 are there and how many are below 500.
• build 2 strings with the numbers.