Which of the following principle does queue use?

Which of the following principle does queue use?

(A). LIFO

(B). FIFO

(C). Both

(D). None of these

Question’s Answer: FIFO

FIFO means first element added to the queue is the first one to be removed from queue.

Example

#include <iostream>
#include <queue>

using namespace std;

int main()
{
    // Create an empty queue
    queue<int> Queue;

    // Push elements onto the queue
    Queue.push(5);
    Queue.push(8);
       cout << "Queue size: " << Queue.size() << endl<< endl;

    // Access the front and back elements of the queue
    cout << "Front element: " << Queue.front() << endl<< endl;
    cout << "Back element: " << Queue.back() << endl<< endl;

    // Pop elements from the queue
    Queue.pop();
    Queue.pop();

    // Get the new size of the queue
    cout << "Queue size after two pops: " << Queue.size() << endl<< endl;

    // Check if the queue is empty
    if (Queue.empty()) {
        cout << "Queue is empty" << endl<< endl;
    } else {
        cout << "Queue is not empty" << endl<< endl;
    }

    return 0;
}

Output

Queue size: 2
Front element: 5
Back element: 8
Queue size after two pops: 0
Queue is empty