deque assign() function in C++ STL Last Updated : 02 Nov, 2018 Comments Improve Suggest changes Like Article Like Report The deque::assign() is a built-in function in C++ STL which is used to assign values to the same or different deque container. On being called more than once in the same program, the function destroys the values of the previous elements and re-assigns new set of elements to the container. Syntax: deque_name.assign(size, val) Parameters: The function accepts two parameters which are described below: size: it specifies the number of values to be assigned to the container. val: it specifies the value to be assigned to the container. Return Value: The function returns nothing. Below programs illustrate the above function: Program 1: CPP // CPP program to demonstrate the // deque::assign() function #include <bits/stdc++.h> using namespace std; int main() { deque<int> dq; // assign 5 values of 10 each dq.assign(5, 10); cout << "The deque elements: "; for (auto it = dq.begin(); it != dq.end(); it++) cout << *it << " "; // re-assigns 10 values of 15 each dq.assign(10, 15); cout << "\nThe deque elements: "; for (auto it = dq.begin(); it != dq.end(); it++) cout << *it << " "; return 0; } Output: The deque elements: 10 10 10 10 10 The deque elements: 15 15 15 15 15 15 15 15 15 15 Syntax: deque1_name.assign(iterator1, iterator2) Parameters: The function accepts two parameters which are described below: iterator1: it specifies the iterator which points to the starting element of container(deque, array, ...) whose elements are to be transferred to deque1. iterator2: it specifies the iterator which points to the last element of a container(deque, array, ...) whose elements are to be transferred to deque1 Return Value: The function returns nothing. Below programs illustrate the above function: Program 1: CPP // CPP program to demonstrate the // deque::assign() function #include <bits/stdc++.h> using namespace std; int main() { deque<int> dq; // assign 5 values of 10 each dq.assign(5, 10); cout << "The deque elements: "; for (auto it = dq.begin(); it != dq.end(); it++) cout << *it << " "; deque<int> dq1; // assigns all elements from // the second position to deque1 dq1.assign(dq.begin() + 1, dq.end()); cout << "\nThe deque1 elements: "; for (auto it = dq1.begin(); it != dq1.end(); it++) cout << *it << " "; return 0; } Output: The deque elements: 10 10 10 10 10 The deque1 elements: 10 10 10 10 Comment More infoAdvertise with us Next Article deque rbegin() function in C++ STL gopaldave Follow Improve Article Tags : Misc C++ Programs C++ STL CPP-Functions cpp-deque +2 More Practice Tags : CPPMiscSTL Similar Reads Deque in C++ STL In C++, deque container provides fast insertion and deletion at both ends. Stands for Double Ended QUEue, it is a special type of queue where insertion and deletion operations are possible at both the ends in constant time complexity.Example:C++#include <iostream> #include <deque> using 6 min read Commonly Used Methodsdeque::push_front() in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 2 min read deque::push_back() in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 2 min read deque::pop_front() and deque::pop_back() in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 4 min read Deque::front() and deque::back() in C++ STLDeque or Double Ended queues are sequence containers with the feature of expansion and contraction on both ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also at the beginning. Unlike vectors, contiguous storage allocation may 4 min read deque insert() function in C++ STLThe deque::insert() function is a built-in function in C++ which is used to insert elements in the deque. The insert() function can be used in three ways: Extends deque by inserting a new element val at a position.Extends deque by inserting n new element of value val in the deque.Extends deque by in 3 min read deque::begin() and deque::end in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 3 min read Deque::empty() and deque::size() in C++ STLDeque or Double Ended queues are sequence containers with the feature of expansion and contraction on both ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also at the beginning. Unlike vectors, contiguous storage allocation may 4 min read deque::clear() and deque::erase() in C++ STLDeque or Double-ended queues are sequence containers with the feature of expansion and contraction on both ends. They are similar to vectors, but are more efficient in the case of insertion and deletion of elements at the end, and also at the beginning. Unlike vectors, contiguous storage allocation 5 min read Other Member Methodsdeque max_size() function in C++ STLThe deque::max_size() is a built-in function in C++ STL which returns the maximum number of elements that a deque container can hold. Syntax: deque_name.max_size()Parameters: The function does not accept any parameters. Return Value: The function returns the maximum number of elements that a deque c 1 min read deque assign() function in C++ STLThe deque::assign() is a built-in function in C++ STL which is used to assign values to the same or different deque container. On being called more than once in the same program, the function destroys the values of the previous elements and re-assigns new set of elements to the container. Syntax: de 2 min read deque rbegin() function in C++ STLThe deque::rbegin() is an inbuilt function in C++ STL which returns a reverse iterator which points to the last element of the deque (i.e., its reverse beginning). Syntax: deque_name.rbegin()Parameter: This function does not accept any parameters. Return value: It returns a reverse iterator which po 2 min read deque rend() function in C++ STLThe deque::rend() is an inbuilt function in C++ STL which returns a reverse iterator which points to the position before the beginning of the deque (which is considered its reverse end). Syntax: deque_name.rend()Parameter: This function does not accept any parameters. Return value: It returns a reve 2 min read deque cbegin() in C++ STLThe cbegin() method in deque is a function in C++ STL which returns an iterator pointing to the first element of the container. Syntax: deque_name.cbegin() Return value: It returns a constant iterator pointing to the first element of the deque. This means, that the iterator can be used to traverse t 2 min read deque cbegin() in C++ STLThe cbegin() method in deque is a function in C++ STL which returns an iterator pointing to the first element of the container. Syntax: deque_name.cbegin() Return value: It returns a constant iterator pointing to the first element of the deque. This means, that the iterator can be used to traverse t 2 min read deque::operator= and deque::operator[] in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 4 min read deque::at() and deque::swap() in C++ STLDeque or Double ended queues are sequence containers with the feature of expansion and contraction on both the ends. They are similar to vectors, but are more efficient in case of insertion and deletion of elements at the end, and also the beginning. Unlike vectors, contiguous storage allocation may 4 min read How Deque Works Internally in C++? Prerequisite: Deque in C++ Deque or Double Ended Queue is a generalized version of the Queue data structure that allows insert and deletion at both ends. It supports the access of elements in O(1) time complexity and the insertion and deletion of elements from front and back are both done with O(1) 4 min read Deque of Pairs in C++ with Examples What is a deque? In C++, the deque is a sequence container and it is also known by the name, double-ended queue. As the name implies, a deque allows insertion and deletion from both ends. Although a deque is similar to a vector, deques are more efficient compared to vectors. In vectors, contiguous s 5 min read Difference between Queue and Deque in C++ Queue: A Queue is a linear data structure that follows a First In First Out (FIFO) order in which the operations are performed. It is a type of container adaptor where elements are inserted into one end of the container and deleted from the other. Functions: empty(): Tests whether the queue is empty 4 min read Deque vs Vector in C++ STL Deque in C++ Standard Template Library (STL) Double-ended queues are sequence containers with the feature of expansion and contraction on both ends. They are similar to vectors but support inserting and deleting the first element in O(1). Unlike vectors, contiguous storage allocation is not guarante 2 min read How to check/find an item in Dequeue using find() method find() function finds the element in the given range of numbers. Returns an iterator to the first element in the range [first, last) that compares equal to the value to be searched. If no such element is found, the function returns last. Syntax: InputIterator find (InputIterator first, InputIterator 6 min read Like