Sets are containers that store unique elements following a specific order. Internally, the elements in a set are always sorted. Sets are typically implemented as binary search trees.
The set class provides a member function, set::size() function is used to return the size of the set container or the number of elements in the set container.
Syntax
set_name.size();
Return Value
- It returns the number of elements in the set container.
Errors and Exceptions
- It has a no exception throw guarantee.
- Shows an error when a parameter is passed.
Example
C++
#include <bits/stdc++.h>
using namespace std;
int main()
{
set< char > set1, set2;
for ( int i = 0; i < 4; i++) {
set1.insert( 'a' + i);
}
cout << "set1 size: " << set1.size();
cout << endl;
cout << "set2 size: " << set2.size();
return 0;
}
|
Outputset1 size: 4
set2 size: 0
Note: This function works in constant time complexity.