unordered_multimap cbegin() function in C++ STL
The unordered_multimap::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_multimap_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_multimap container.
Return Value: It returns a constant iterator. It cannot be used to change the value of the unordered_multimap element.
Below programs illustrates the above function:
Program 1:
#include <bits/stdc++.h>
using namespace std;
int main()
{
unordered_multimap< int , int > sample;
sample.insert({ 1, 2 });
sample.insert({ 3, 4 });
sample.insert({ 3, 4 });
sample.insert({ 2, 3 });
sample.insert({ 2, 3 });
cout << "Key and Elements : \n" ;
for ( auto it = sample.begin(); it != sample.end(); it++)
cout << " " << it->first << "\t "
<< it->second << endl;
auto it = sample.begin();
cout << "\nThe first element and key: "
<< it->first << " " ;
cout << it->second;
return 0;
}
|
Output:
Key and Elements :
2 3
2 3
1 2
3 4
3 4
The first element and key: 2 3
Program 2:
#include <bits/stdc++.h>
using namespace std;
int main()
{
unordered_multimap< int , int > sample;
sample.insert({ 1, 2 });
sample.insert({ 3, 4 });
sample.insert({ 3, 4 });
sample.insert({ 2, 3 });
sample.insert({ 2, 3 });
cout << "Key and Elements of first bucket: \n" ;
for ( auto it = sample.cbegin(1); it != sample.cend(1); it++)
cout << " " << it->first << "\t "
<< it->second << endl;
auto it = sample.cbegin(1);
cout << "\nThe first element and key in first bucket: "
<< it->first << " " ;
cout << it->second;
return 0;
}
|
Output:
Key and Elements of first bucket:
1 2
The first element and key in first bucket: 1 2
Last Updated :
08 Aug, 2018
Like Article
Save Article
Share your thoughts in the comments
Please Login to comment...