Java Program to Separate Odd and Even Numbers from an Array

In this post, you will learn how to separate odd and even numbers from an array using the Java programming language.

Algorithm: Separate Odd and Even Numbers

This algorithm ensures that the numbers are separated into two distinct arrays based on whether they are odd or even.

1. Initialize empty arrays:
   oddArray = []
   evenArray = []

2. For each element in the original array:
     If element is even:
         Append element to evenArray
     Else:
         Append element to oddArray

3. Output evenArray
4. Output oddArray

Java program to separate odd and even numbers

import java.util.Arrays;

public class SeparateOddEven {
    public static void main(String[] args) {
        int[] array = {21, 45, 6, 31, 88, 91, 66};
        System.out.println("Original Array: " + Arrays.toString(array));

        // Arrays to store odd and even numbers
        int[] oddArray = new int[array.length];
        int[] evenArray = new int[array.length];

        int oddIndex = 0, evenIndex = 0;

        // Separate odd and even numbers
        for (int num : array) {
            if (num % 2 == 0) {
                evenArray[evenIndex++] = num;
            } else {
                oddArray[oddIndex++] = num;
            }
        }

        // Trim arrays to remove trailing zeros
        oddArray = Arrays.copyOf(oddArray, oddIndex);
        evenArray = Arrays.copyOf(evenArray, evenIndex);

        System.out.println("Even Numbers: " + Arrays.toString(evenArray));
        System.out.println("Odd Numbers: " + Arrays.toString(oddArray));
    }
}

Original Array: [21, 45, 6, 31, 88, 91, 66]
Even Numbers: [6, 88, 66]
Odd Numbers: [21, 45, 31, 91]

Code Explanation:

• Input Array: {21, 45, 6, 31, 88, 91, 66}
• The program separates the array into two new arrays: one for odd numbers and one for even numbers.
• It iterates over the original array, checking each element to see if it’s even or odd.
• Even numbers are added to evenArray, and odd numbers are added to oddArray.
• The arrays are then trimmed to remove unused elements (trailing zeros).

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