multimap empty() function in C++ STL

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: 

multimap is empty
multimap is not empty

Time Complexity : O(1)