Queues are an abstract data type, specifically designed to operate in a FIFO context (first-in-first-out). The elements are inserted into one end of the container and extracted from the other. They are a type of container adaptor in the C++ Standard Library. The queue::pop()
is a method available in the STL which removes the oldest element present in the queue and effectively reduces the size by one.
Syntax:
queue_name.pop();
Parameters: The queue::pop()
does not accept any parameters
Return value: none
Example of queue::pop() method
#include <iostream> #include <queue> using namespace std; void print(queue<int> q) { while (!q.empty()) { cout<<q.front()<<" "; q.pop(); } cout<<endl; } int main () { queue<int> q1; for(int i = 1; i <= 5; i++) q1.push(i); cout<<"Before pop: \n"; print(q1); q1.pop(); cout<<"After pop: \n"; print(q1); return 0; }
Output:
Before pop: 1 2 3 4 5 After pop: 2 3 4 5