In this shot, we will learn how to *swap two elements* in a #key# one-dimensional array: the simplest form of array in C++. It is a group of elements that have the same datatype and same name. #key#.

 
# Code
## Example 1: Manually swapping elements

In this algorithm, we use a *temporary variable* to swap the elements.

1. The value of the first element (`arr[0]`) is stored in `temp`. 

2. The value of the second index (`arr[2]`) is then assigned to the first index (`arr[0]`).

3. The value of `temp` is then assigned to the second index (`arr[2]`).


#include <iostream>
using namespace std;

// user defined function to print array
void printArr (int arr[], int size) {
    for(int i = 0; i < size; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}

int main() {

  // declare array
  const int size = 5;
  int arr[size] = {5, 2, 3, 4, 1};

  // temp variable to aid in swapping
  int temp;

  cout << "Original array: ";
  printArr(arr, size);

  // swapping first and last element
  temp = arr[0];
  arr[0] = arr[size - 1];
  arr[size - 1] = temp;

  cout << "Array with first and last element swapped: ";
  printArr(arr, size);

  return 0;
}

 
## Example 2: Using `std::swap()` to swap elements

The built-in `swap()` function can swap two values in an `array`.

---
```
template <class T> void swap (T& a, T& b);
```
---

The `swap()` function takes two arguments of any #key# data type: this specifies the type of data that a variable can store, such as integer, floating, or character, etc. #key#, i.e., the two values that need to be swapped.
##
## Return value
This function returns nothing.

#include <iostream>
using namespace std;

// user defined ftn to print array
void printArr (int arr[], int size) {
    for(int i = 0; i < size; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}

int main() {

  // declare array
  const int size = 5;
  int arr[size] = {5, 2, 3, 4, 1};

  // temp variable to aid in swapping
  int temp;

  cout << "Original array: ";
  printArr(arr, size);

  // swapping first and last element
  swap(arr[0], arr[size - 1]);

  cout << "Array with first and last element swapped: ";
  printArr(arr, size);

  return 0;
}

How to swap two elements in 1D array in C++

Manually swap elements using a temporary variable or use C++'s built-in std::swap() function.

How to swap two elements in 1D array in C++

Code

Example 1: Manually swapping elements

Example 2: Using std::swap() to swap elements

Return value

Example 2: Using `std::swap()` to swap elements