How to reverse an Array in C++?

In today’s fast – paced digital era, having a good command over programming languages proves to be quite beneficial for an individual. C++ is one such high – in – demand language, which is having a quite crucial value. In this article, you’ll be learning how you can reverse an Array in C++.

Given an array arr[] of elements (integers) Array arr[] : 1, 5, 7, 8, 9, 2, 3, 11

After reversal, the new array arr[] will be   Array arr[]:   11, 3, 2, 9, 8, 7, 5, 1

Approach

• Consider 2 pointers start and end. Start will initially point to beginning of the array and end will point to end of the array.
• Swap the elements of the start and end positions.
• Increment the start pointer and decrement the end pointer.
• Repeat the process until start is greater or equal to  the end pointer.

 
 #include<iostream>
 #include<bits/stdc++.h>

 using namespace std;
 class ReverseArray
 {
     public:
     //Method to reverse the array
     void reverseArray(vector &arr, int size)
     {
         //checking if array size is 1 or 0 
         if(size == 0 || size == 1) return;
         //initialising start with 0
         int start = 0;
         //initialising end with size of array -1 as index start from 0
         int end   = size - 1;
         //looping through while start is less than end
         while(start < end)        
                         {         
    //swapping the values
             swap(arr[start],arr[end]);
             //increment start
             start++;
             //decrement end
             end--;
         }
     }
     //method to print elements of vector
     void printVector(vector&arr, int arr_size)
     {
         for(int i=0;i<arr_size;i++)
         {
             cout<<arr[i]<<" ";
         }
         cout<<endl;
     }
 };
 int main()
 {
     //creating the ReverseAray object
     ReverseArray ra;
     vector arr = {1,4,3,5,7,8,9,8,2,6};
     int arr_size = arr.size();
     cout<<"Before Reversal"<<endl;
     ra.printVector(arr, arr_size);
     ra.reverseArray(arr, arr_size);
     cout<<"After Reversal"<<endl;
     ra.printVector(arr, arr_size);
 return 0;
 }

Output:

Before Reversal
1 4 3 5 7 8 9 8 2 6
After Reversal
6 2 8 9 8 7 5 3 4 1

Also Read

Introduction to C++ STL

Basic Operations on Matrices in C++

Basic Operations on Matrices in C++

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