unordered_multiset cbegin() function in C++ STL

Last Updated : 02 Aug, 2018

The unordered_multiset::cbegin() is a built-in function in C++ STL which returns a constant iterator pointing to the first element in the container or to the first element in one of its bucket. Syntax:

unordered_multiset_name.cbegin(n)

Parameters: The function accepts one parameter. If a parameter is passed, it returns a constant iterator pointing to the first element in the bucket. If no parameter is passed, then it returns a constant iterator pointing to the first element in the unordered_multiset container. Return Value: It returns a constant iterator. It cannot be used to change the value of the unordered_multiset element. Below programs illustrates the above function: Program 1:

CPP

// C++ program to illustrate the // unordered_multiset::cbegin() function #include <bits/stdc++.h> using namespace std; int main() {  // declaration  unordered_multiset<int> sample;  // inserts element  sample.insert(10);  sample.insert(11);  sample.insert(15);  sample.insert(13);  sample.insert(14);  // prints all element  cout << "Elements: ";  for (auto it = sample.cbegin(); it != sample.cend(); it++)  cout << *it << " ";  auto it = sample.cbegin();  // print the first element  cout << "\nThe first element: " << *it;  return 0; }

Program 2:

CPP

// C++ program to illustrate the // unordered_multiset::cbegin() function #include <bits/stdc++.h> using namespace std; int main() {  // declaration  unordered_multiset<char> sample;  // inserts element  sample.insert('a');  sample.insert('b');  sample.insert('c');  sample.insert('x');  sample.insert('z');  // print the first element  auto it = sample.cbegin();  cout << "The first element: " << *it;  it++;  cout << "\nThe second element: " << *it;  cout << "\nElements: ";  // prints all element  for (auto it = sample.cbegin(); it != sample.cend(); it++)  cout << *it << " ";  return 0; }

Program 3:

CPP

// C++ program to illustrate the // unordered_multiset::cbegin() function #include <bits/stdc++.h> using namespace std; int main() {  // declaration  unordered_multiset<char> sample;  // inserts element  sample.insert('a');  sample.insert('b');  sample.insert('c');  sample.insert('x');  sample.insert('z');  // print the first element  cout << "The first element in first bucket : " << *sample.cbegin(1);  cout << "\nElements in first bucket: ";  // prints all element  for (auto it = sample.cbegin(1); it != sample.cend(1); it++)  cout << *it << " ";  return 0; }