map count() function in C++ STL
The map::count() is a built-in function in C++ STL which returns 1 if the element with key K is present in the map container. It returns 0 if the element with key K is not present in the container.
Syntax:
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map_name.count(key k)
Parameters: The function accepts a mandatory parameter k which specifies the key to be searched in the map container.
Return Value: The function returns the number of times the key K is present in the map container. It returns 1 if the key is present in the container as the map only contains a unique key. It returns 0 if the key is not present in the map container.
Below program illustrates the above function:
// C++ program to illustrate// the map::count() function#include <bits/stdc++.h>using namespace std; int main(){ // initialize container map<int, int> mp; // insert elements in random order mp.insert({ 2, 30 }); mp.insert({ 1, 40 }); mp.insert({ 3, 60 }); mp.insert({ 4, 20 }); mp.insert({ 5, 50 }); // checks if key 1 is present or not if (mp.count(1)) cout << "The key 1 is present\n"; else cout << "The key 1 is not present\n"; // checks if key 100 is present or not if (mp.count(100)) cout << "The key 100 is present\n"; else cout << "The key 100 is not present\n"; return 0;} |
Output:
The key 1 is present The key 100 is not present
