Counting odd even and zeros in array java-CodePudding

How can I add the codes to find the zeros in the array of this program? This code can count even and odd. Should I do a different statement, or can I just add another if else statement?

import java.util.Scanner;

public class num
{
   public static void main(String args[]) {
       
       final int NUM_COUNT = 20;
       Scanner in = new Scanner(System.in);
       int i = 0;
       
       int arr[] = new int[NUM_COUNT];
       int even[] = new int[NUM_COUNT];
       int odd[] = new int[NUM_COUNT];
       
       System.out.println("Enter 20 numbers:");
       for (i = 0; i < NUM_COUNT; i  ) {
           arr[i] = in.nextInt();
       }
       
       int eIdx = 0, oIdx = 0;
       for (i = 0; i < NUM_COUNT; i  ) {
           if (arr[i] % 2 == 0)
               even[eIdx  ] = arr[i];
           else
               odd[oIdx  ] = arr[i];
       }
       
       System.out.println("Even Numbers:");
       for (i = 0; i < eIdx; i  ) {
           System.out.print(even[i]   " ");
       }
       
       System.out.println("\nOdd Numbers:");
       for (i = 0; i < oIdx; i  ) {
           System.out.print(odd[i]   " ");
       }
   }
}

CodePudding user response：

No need to create extra arrays. Counting can be done with just one integer.

int zeroCount = 0;
for (i = 0; i < NUM_COUNT; i  ) {
    if (arr[i] == 0) {
        zeroCount  ;
    }
}
System.out.println("Zeros: "   zeroCount);

I've changed the output style to clearly label what is being output here. Something to consider for the rest of the code.

CodePudding user response：

In addition to the iterative solution of @candied_orange answer, I'd like to contribute offering a stream implementation. Just stream the elements, filter for the ones that are equal to zero and finally count the number of elements in the stream.

long numZeros = Arrays.stream(arr).filter(i -> i == 0).count();
System.out.println("Num of zeros: "   numZeros);

CodePudding user response：

Declare arrays for zero & counter similar to even and odd :

int zero[] = new int[NUM_COUNT];
int zIdx=0;

And modify your if / else something like:

if (arr[i] == 0)
  zero[zIdx  ] = arr[i];
else if (arr[i] % 2 == 0)
      even[eIdx  ] = arr[i];
 else
    odd[oIdx  ] = arr[i];