XOR of All Elements in C, C++, Java & Python – Code with Explanation & Examples in Short and Simple

   

C Program

#include <stdio.h>

int xorAll(int arr[], int n) {
    if (n == 0) return 0;
    return arr[n - 1] ^ xorAll(arr, n - 1);
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int n = sizeof(arr) / sizeof(arr[0]);
    printf("XOR of all elements: %d\n", xorAll(arr, n));
    return 0;
}

C Output

XOR of all elements: 1

C++ Program

#include <iostream>
using namespace std;

int xorAll(int arr[], int n) {
    if (n == 0) return 0;
    return arr[n - 1] ^ xorAll(arr, n - 1);
}

int main() {
    int arr[] = {5, 1, 2, 3};
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << "XOR of all elements: " << xorAll(arr, n) << endl;
    return 0;
}

C++ Output

XOR of all elements: 5

JAVA Program

public class Main {
    static int xorAll(int[] arr, int n) {
        if (n == 0) return 0;
        return arr[n - 1] ^ xorAll(arr, n - 1);
    }

    public static void main(String[] args) {
        int[] arr = {7, 7, 2, 2, 5};
        System.out.println("XOR of all elements: " + xorAll(arr, arr.length));
    }
}

JAVA Output

XOR of all elements: 5

Python Program

def xor_all(arr, n):
    if n == 0:
        return 0
    return arr[n - 1] ^ xor_all(arr, n - 1)

arr = [8, 1, 2, 3, 8]
print(f"XOR of all elements: {xor_all(arr, len(arr))}")

Python Output

XOR of all elements: 2

Explanation

Example

Let's take the array {1, 2, 3, 4, 5}. The XOR operation is similar to a toggle:

1 ^ 2 = 3  

3 ^ 3 = 0  

0 ^ 4 = 4  

4 ^ 5 = 1  

Thus, the result at the end will be 1. Recursion here is done by taking the last element and XORing it with the XOR of the rest of the elements, until there are no more elements left.

Real-Life Analogy

Suppose you had a collection of light switches such that turning the same switch twice switches it off. XOR is exactly like this: when a number occurs twice, it "cancels out." When you XOR everything together, all the repeated "paired up" values disappear. That's why XOR is ideal for determining the unique single element in a list where all other elements occur twice.

Why It Matters

XOR is an efficient low-level bitwise operation. It's commonly utilized in encryption, checksums, error detection, and efficient algorithms for searching for missing or unique elements. Due to the associativity and commutativity of XOR, you can reorder and merge elements in any order without altering the outcome.

Learning Insights

This exercise does two things: recursion on arrays and the properties of XOR. XOR gives 1 when bits are different and 0 when they are equal, and it is well suited to "difference tracking" in the binary case. Recursion in this case illustrates how you can reduce problems to smaller and smaller subproblems until a trivial case is left.

Interview and Real-World Usage

In coding interviews, XOR is often a trick solution to avoid extra space when tracking duplicates. In real systems, XOR is used in RAID storage parity, network packet validation, and graphics programming for pixel blending. This recursive approach is not the fastest, but it’s excellent for demonstrating understanding of both recursion and bitwise logic.

SEO-Friendly Closing

Calculating the XOR of all elements of an array through recursion is a basic problem that combines bitwise operations with recursive thinking. Having a good grasp of XOR assists in problems such as finding missing numbers, identifying unique elements, and performing lightweight encryption. In C, C++, Java, or Python, this idea is very essential for effective algorithm design and a good skill in coding interviews and performance-critical code.