HashMap containsKey() Method in Java

The containsKey() method in Java's HashMap class is used to check whether a specific key is present in the map. It returns true if the key exists, otherwise false. This method is essential for validating the presence of keys before accessing their corresponding values. Learn more about how the containsKey() method works with various data types, and explore efficient usage of HashMap through hands-on exercises in Java Programming. This method’s time complexity is O(1) on average, making it a fast operation for key checks.

For more details, please read the GeeksforGeeks article: HashMap containsKey() Method in Java.