what does map.count() return in c++

Explanation of map.count() in C++

In C++, map.count() is a member function of the std::map container class. It is used to count the number of elements in the map that have a specific key. The function returns an integer value representing the count.

Here is an example usage of map.count():

#include <iostream>
#include <map>

int main() {
    std::map<int, std::string> myMap;
    myMap[1] = "one";
    myMap[2] = "two";
    myMap[3] = "three";

    int key = 2;
    int count = myMap.count(key);

    std::cout << "The count of key " << key << " is: " << count << std::endl;

    return 0;
}

In this example, myMap.count(key) is used to count the number of elements in myMap that have the key 2. The result is stored in the variable count and then printed to the console.

The output of the above code will be:

The count of key 2 is: 1

This means that there is one element in the map with the key 2.

Please note that the count() function returns either 0 or 1 because the keys in a std::map are unique. If the key is present in the map, the count will be 1; otherwise, it will be 0.

I hope this explanation helps! Let me know if you have any further questions.