Open In App

multimap empty() function in C++ STL

Last Updated : 12 Jun, 2023
Comments
Improve
Suggest changes
1 Likes
Like
Report

The multimap::empty() is a boolean type observer function in C++ STL which tells whether the container is empty or not. This function returns true when the multimap container is empty (i.e. the size of the container is 0). Being an observer function it does not modify the multimap in any way. 

Syntax:

multimap1.empty()

Return Value: This method returns a boolean type value. It returns true when multimap is empty else returns false. 

Below program illustrate the multimap::empty() function: 

CPP 
// C++ program to demonstrate 
// std::multimap::empty 

#include <iostream> 
#include <map> 

using namespace std; 

int main() 
{ 

    // declaring multimap 
    multimap<char, int> mmap; 

    // checking if mmap is empty or not 
    if (mmap.empty()) 
        cout << "multimap is empty\n"; 

    // inserting values to mmap 
    // thus making it non empty 
    mmap.insert(pair<char, int>('a', 26)); 
    mmap.insert(pair<char, int>('b', 30)); 
    mmap.insert(pair<char, int>('c', 44)); 

    // checking that mmap is now not empty 
    if (mmap.empty()) 
        cout << "multimap is empty\n"; 
    else
        cout << "multimap is not empty\n"; 

    return 0; 
}
Output:
multimap is empty
multimap is not empty

Time Complexity : O(1)


K

Kushagra7744
Improve
Article Tags :

Explore

Lightbox