Reverse an Array in C, C++, Java & Python – Code with Explanation & Examples in Short and Simple

   

C Program

void reverse(int a[], int n) {
    for (int i = 0; i < n/2; i++) {
        int t = a[i];
        a[i] = a[n-1-i];
        a[n-1-i] = t;
    }
}

C Output

Input: a = {1, 2, 3, 4, 5}

Output: 5 4 3 2 1

C++ Program

void reverse(vector<int>& a) {
    int n = a.size();
    for (int i = 0; i < n/2; i++)
        swap(a[i], a[n-1-i]);
}

C++ Output

Input: a = {10, 20, 30}

Output: 30 20 10

JAVA Program

void reverse(int[] a) {
    int n = a.length;
    for (int i = 0; i < n/2; i++) {
        int t = a[i];
        a[i] = a[n-1-i];
        a[n-1-i] = t;
    }
}

JAVA Output

Input: a = {3, 6, 9}

Output: 9 6 3

Python Program

def reverse(a):
    a.reverse()

Python Output

Input: a = [7, 8, 9, 10]

Output: [10, 9, 8, 7]

In-Depth Explanation

Example

If we have the array [1, 2, 3, 4, 5], the reverse of it would be [5, 4, 3, 2, 1]. The principle is straightforward: we switch the first and last ones, then move inwards and continue switching until we are at the middle. This method uses only a single loop that goes halfway through the array.

Real-Life Analogy

Suppose there is a queue of individuals waiting for a bus. Suddenly, the bus comes from the other side, and the individual at the back must get on first now. You just reverse the queue so the person at the end becomes the first one and the person at the front becomes the last one. That's what array reversing does — it reverses the elements' order.

This is similar to reading a book in reverse — you begin at the end and move towards the front.

Why It Matters

Array reversal is one of the most used array manipulations in programming. It will help you learn:

Array indexing

In-place swapping

Loop control and optimization

It's an ideal problem to construct your base in iteration, indexing, and memory-optimized solutions since no additional array is needed — we just interchange the values within the same array.

What You Learn from This

This problem shows you how to:

Work with array elements using loops

Reversing data efficiently without extra space usage

Recognize how i and n-1-i are referencing symmetrical positions

Consider array borders and conditions in a clear manner

These are key concepts in sorting algorithms, stack problems, and memory-sensitive applications.

Interview Relevance and Real Projects

Array reversal is typically asked in:

Entry-level interviews for checking basic logic

As a sub-task in bigger problems such as rotation, palindrome checks, and data formatting

Technical exams and aptitude rounds

In real-life cases, it is applied in:

Data structure operations such as stack and queues

Undo/redo functionality

Cryptography and encoding logic

Visual layout flipping in games or UIs

SEO-Optimized Explanation

Array reversal is a basic programming concept applied across various real-world and technical contexts. In C, C++, Java, and Python, one may reverse an array by employing plain loops or predefined functions such as reverse(). Array reversal is a time-honored problem in learning array manipulation, indexing, and memory efficiency. Array reversal exercise sharpens your logical reasoning and helps you ace coding interviews that involve array and string manipulations. Whether backing up for palindrome verification, list styling, or breaking down a subproblem in sorting, this method is key to learning programming fundamentals and gaining your confidence with data transformations.