What is the difference between map and set

The add method is used to insert elements to treeset. Therefore, it only displays the unique elements. Furthermore, it prints the Set as an ordered list. Map is an interface that represents a mapping between a key and a value. It does not extend the Collection interface.

Therefore, the behavior of Map is different from the usual Collection types. A Map cannot contain duplicate keys, and each key can map to at most one value.

Figure 3: Program with HashMap. The studentList is an object of type Map. The put method is used to insert elements to studentList. HashMap does not maintain the inserted order. It only prints the unique values.

We need map to store array values as key and frequencies as value. Skip to content. Change Language. Related Articles. Table of Contents. Save Article. References: 1. Rate this post. We are sorry that this post was not useful for you!

Tell us how we can improve this post? Submit Feedback. Thanks for reading. Like us? Refer us to your friends and help us grow. LinkedHashMap allows one null key and many null values. TreeMap doesn't allow null key but allow many null values. Hashtable doesn't allow null key or null values. ConcurrentHashMap doesn't allow null key or null values.

ConcurrentSkipListMap doesn't allow null key or null values. Getting element on specific index. List implementations provide get method to get element on specific index in java.

Method returns element on specified index. Get method directly gets element on specified index. Hence, offering O 1 complexity. Set implementations does not provide any such get method to get element on specified index in java.

Map implementations does not provide any such get method to get element on specified index in java. Implementing classes. Set does not provide anything like listIterator. It simply return Iterator in java. Map provides three type of iterators -.