What does retainAll () do in Java?
What does set retainAll do?
How does Addall work in Java?
|elements||Elements are the elements to be inserted into c.||Required|
What is the use of retainAll collection C method from collection interface?
What is LinkedList Java?
What is set Java?
What is difference between collection and collections?
Collection vs Collections in Java with Example.
|It is an interface.||It is a utility class.|
|It is used to represent a group of individual objects as a single unit.||It defines several utility methods that are used to operate on collection.|
What is collections API in Java?
Which is faster and uses less memory?
What is map in Java?
Which collection is faster in Java?
Is HashMap part of collection?
HashMap is a part of Java’s collection since Java 1.2. It provides the basic implementation of the Map interface of Java. It stores the data in (Key, Value) pairs.
Can maps have null keys?
Can Map have duplicate keys?
Is Java Map a collection?
Because a Map is not a true collection, its characteristics and behaviors are different than the other collections like List or Set. A Map cannot contain duplicate keys and each key can map to at most one value.
Can we iterate HashMap?
Can HashMap be null?
What is a Multimap Java?
How many ways can you iterate a Map in Java?
What is iterator in Java?
How do you iterate through a set?
- Obtain the iterator by calling the iterator() method.
- You can use while or for loop along with hasNext(), which returns true if there are more elements in the Set.
- Call the next() method to obtain the next elements from Set.