check if a key is present in a hashmap code example

Example 1: check if map contains key java

if (map.containsKey(key)) {
       // Okay, there's a key but the value is null
    } else {
       // Definitely no such key
    }

Example 2: check if map key has value cpp

#include<map>

int main(){

  	map<int,char> m;
  	
  	char ch = '!';
  
	if (m.find(ch) != m.end()) {
		std::cout << "Key found";
	} else {
		std::cout << "Key not found";
	}
  
	return 0;
}