Collections in Java

The methods to override are equals() and hashCode(). For the HashMap class in Java, the key class should override the hashCode() and equals() methods. These methods are crucial for proper functioning of the HashMap as they determine how keys are stored and retrieved in the underlying data structure. Here’s a brief explanation of each method: … Read more

Collections.synchronizedMap(new HashMap()); Collections.synchronizedList(List<T> list) In Java, if you want to make a Map or List thread-safe or synchronized, you can use the Collections.synchronizedMap and Collections.synchronizedList methods, respectively. These methods return synchronized versions of the provided Map or List. Here’s how you can use them: For a Map: java Map<String, Object> synchronizedMap = Collections.synchronizedMap(new HashMap<>()); For … Read more

Iterator : Iterator takes the place of Enumeration in the Java collections framework. One can traverse throughr the the collection with the help of iterator in forward direction only and Iterators allow the caller to remove elements from the underlying collection during the iteration with well-defined semantics ListIterator: An iterator for lists that allows one to traverse … Read more

HashSet : HashSet does not allow duplicate values. It provides add method rather put method. You also use its contain method to check whether the object is already available in HashSet. HashSet can be used where you want to maintain a unique list. HashMap : It allows null for both key and value. It is unsynchronized. So come … Read more

The properties class is a subclass of Hashtable that can be read from or written to a stream. It also provides the capability to specify a set of default values to be used. In Core Java, the Properties class is a class that represents a persistent set of properties, which can be loaded from or … Read more