unordered_set cend() function in C++ STL
Last Updated :
05 Jun, 2023
The unordered_set::cend() method is a built-in function in C++ STL which is used to return a const_iterator pointing to past-the-end element in the unordered_set container or in one of it’s bucket. This function does not directly point to any element in the container. It is only used to denote the end of a container or the open end of a range as in [cbegin, cend).
Note: A const_iterator can only be used to access elements, it cannot modify the elements present in the container.
Syntax:
unordered_set_name.cend(n);
Parameter: This function accepts a single parameter n. This is an optional parameter and specifies the bucket number. If this parameter is not passed then the cend() method will return a const_iterator pointing to the position just after the last element of the container and if this parameter is passed then the cend() method will return a const_iterator pointing to the position just after the last element in a specific bucket in the unordered_set container.
Return Value: This function returns a const_iterator pointing to the position just after the last element in the container or a specified bucket in the container. Below programs illustrate the unordered_set::cend() function:
Program 1:
CPP
#include <iostream>
#include <unordered_set>
using namespace std;
int main()
{
unordered_set< int > sampleSet;
sampleSet.insert(5);
sampleSet.insert(10);
sampleSet.insert(15);
sampleSet.insert(20);
sampleSet.insert(25);
cout << "Elements present in sampleSet are: \n" ;
for ( auto itr = sampleSet.cbegin(); itr != sampleSet.cend();
itr++) {
cout << *itr << endl;
}
return 0;
}
|
Output:
Elements present in sampleSet are:
25
5
10
15
20
Program 2:
CPP
#include <iostream>
#include <unordered_set>
using namespace std;
int main()
{
unordered_set<string> sampleSet;
sampleSet.insert( "Welcome" );
sampleSet.insert( "To" );
sampleSet.insert( "GeeksforGeeks" );
sampleSet.insert( "Computer Science Portal" );
sampleSet.insert( "For Geeks" );
cout << "Elements present in sampleSet are: \n" ;
for ( auto itr = sampleSet.cbegin(); itr != sampleSet.cend();
itr++) {
cout << *itr << endl;
}
return 0;
}
|
Output:
Elements present in sampleSet are:
Welcome
To
GeeksforGeeks
For Geeks
Computer Science Portal
Time complexity: O(1)
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