calculate number of occurrences in array in java

Question

I want to calculate the number of occurences of a specific number I decide in my main method. Here is what I have to do :

• A function that fills the array with random numbers.

• A function that calculates the number of occurrences,this function may not do any input or output.

• The main function that asks the user for the number and present the result on the screen.

Here is my code in java :

import java.util.Random;
import java.util.Scanner;

public class Code {

    public void calculate(int value) {

        Code c = new Code();
        int count=0;
        for (int n=0; n<array.length; n++) { // the code does not recognize array
            if (array[n]==value) { // the code does not recognize array
                count++;
            }
        }
        System.out.println(count);

    }

    public void addToArray() {

        int k =0;
        int [] array = new int[10];
        int min=0;
        int max=10;
        int diff = max-min;
        while (k<10) {
        Random r = new Random();
        int x = r.nextInt(diff);
        array[k]=x;
        k=k+1;
        }


    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        System.out.println("give your number");
        Code c = new Code();
        Scanner s = new Scanner(System.in);
        int value = s.nextInt();
        c.addToArray();
        c.calculate(value);



    }

}

The only thing I need help with is the calculate method ,, eclipse does not recognize array in the calculate method above ..

How to correct the calculate method to make it recognize array ?

thank you

Pass it to the method in a parameter.

takendarkk
– takendarkk

2016-05-05 12:03:49 +00:00
Commented May 5, 2016 at 12:03 — takendarkk
– takendarkk, Commented May 5, 2016 at 12:03

dryairship · Accepted Answer · 2016-05-05 12:03:21Z

1

Your array is limited to the scope of the method addToArray(). So, it will not be visible to other methods. You need to make it global. Then it will work.

Instead of declaring array in the method addToArray, declare it in your class, like:

public class Code {
    int [] array = new int[10];
    ...

answered May 5, 2016 at 12:03

dryairship

6,0574 gold badges32 silver badges57 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Thilo Over a year ago

Or pass it into the method as a parameter.

dryairship Over a year ago

@Thilo Yes you can. But when an object/variable is to be accessed by multiple methods of the same class, then I prefer to declare it as an instance variable.

Marouane S. · Accepted Answer · 2016-05-05 13:20:03Z

0

if using Java 8 you could update your calculate methode like this :

      public void calculate(int value) {
            System.out.println(Arrays.stream(array)
                                     .filter(i -> i == value)
                                     .count());
      }

By adding this imports to your class :

import java.util.Arrays;

And like mentionned HackerDarshi declaring the attribut array as a member of your class

answered May 5, 2016 at 13:20

Marouane S.

1194 bronze badges

Collectives™ on Stack Overflow

calculate number of occurrences in array in java

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related