[Term Entry] C++ Deque: swap() (#7713)

* Add Cpp swap() deque method

* minor fixes in the codes

* Update swap.md

* format fix

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Author: Allofsimeon

content/cpp/concepts/deque/terms/swap/swap.md

@@ -0,0 +1,110 @@
+---
+Title: '.swap()'
+Description: 'Exchanges the contents of one deque with another of the same type and size.'
+Subjects:
+  - 'Code Foundations'
+  - 'Computer Science'
+Tags:
+  - 'Classes'
+  - 'Containers'
+  - 'Deques'
+  - 'Data Structures'
+CatalogContent:
+  - 'learn-c-plus-plus'
+  - 'paths/computer-science'
+---
+
+The **`.swap()`** [method](https://www.codecademy.com/resources/docs/cpp/methods) exchanges the contents of one [`deque`](https://www.codecademy.com/resources/docs/cpp/deque) with another deque of the same type. After the swap, each deque holds the elements that were originally in the other.
+
+## Syntax
+
+```pseudo
+deque1.swap(deque2);
+```
+
+**Parameters:**
+
+- `deque2`: The deque whose contents will be exchanged with `deque1`.
+
+**Return value:**
+
+This method does not return a value.
+
+## Example
+
+This example demonstrates swapping the contents of two integer deques using `.swap()`:
+
+```cpp
+#include <iostream>
+#include <deque>
+using namespace std;
+
+int main() {
+  deque<int> deque1 = {1, 2, 3};
+  deque<int> deque2 = {10, 20, 30, 40};
+
+  cout << "Before swap:" << endl;
+  cout << "Deque 1: ";
+  for (int num : deque1) cout << num << " ";
+  cout << endl;
+
+  cout << "Deque 2: ";
+  for (int num : deque2) cout << num << " ";
+  cout << endl;
+
+  deque1.swap(deque2);
+
+  cout << "\nAfter swap:" << endl;
+  cout << "Deque 1: ";
+  for (int num : deque1) cout << num << " ";
+  cout << endl;
+
+  cout << "Deque 2: ";
+  for (int num : deque2) cout << num << " ";
+  cout << endl;
+
+  return 0;
+}
+```
+
+The output of this code is:
+
+```shell
+Before swap:
+Deque 1: 1 2 3
+Deque 2: 10 20 30 40
+
+After swap:
+Deque 1: 10 20 30 40
+Deque 2: 1 2 3
+```
+
+## Codebyte Example
+
+This example swaps the contents of two deques containing strings:
+
+```codebyte/cpp
+#include <iostream>
+#include <deque>
+#include <string>
+using namespace std;
+
+int main() {
+  deque<string> dequeA = {"apple", "banana"};
+  deque<string> dequeB = {"cherry", "date"};
+
+  cout << "Before swap:" << endl;
+  cout << "Deque A:";
+  for (const auto& value : dequeA) cout << ' ' << value;
+  cout << "\nDeque B:";
+  for (const auto& value : dequeB) cout << ' ' << value;
+
+  dequeA.swap(dequeB);
+
+  cout << "\n\nAfter swap:" << endl;
+  cout << "Deque A:";
+  for (const auto& value : dequeA) cout << ' ' << value;
+  cout << "\nDeque B:";
+  for (const auto& value : dequeB) cout << ' ' << value;
+}
+```