What is the difference between set and map?

The main difference between Set and Map is that Set is a collection interface subtype while Map is not a collection interface subtype.

An array stores data of the same type. But, after creating an array, it is not possible to change it. Programming languages ​​like Java provide collections to store data dynamically. Allows multiple objects to be stored as a single group. In addition, it is possible to perform operations such as sorting, searching, inserting, and deleting on a collection. The base interface for implementing collections in Java is called Collection. There are several interfaces that extend the collection interface. One of them is Set interface. On the other hand, Map does not extend the Collection interface as it is a separate interface.

Key Areas Covered

1. What is set
     – Definition, Functionality
2. What is map
     – Definition, Functionality
3. What is the difference between set and map?
     – Comparison of key differences

what is established

Set is an interface that extends the collection interface. It cannot contain duplicate values. HashSet and TreeSet implement Set. The set interface provides methods like add, size, etc. to perform operations on the collection. An example is the following.

The HashSet is an object of type Set. You can store ropes. The add method is used to insert elements into the HashSet. Although there are two strings as “apple“, there is only one apple in the output. Therefore, it does not show the elements that already exist in the Set. Also, it prints the set as an unordered list. The size method gives the number of elements in the set.

The array of trees is an object of type Array that can store strings. The add method is used to insert elements into an array of trees. Although there are two strings as “apple”, there is only one apple in the output. Therefore, it only shows the unique items. Also, it prints the set as an ordered list. The size method gives the number of elements in the set.

what is map

The 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 the map is different from the usual collection types. A Map cannot contain duplicate keys, and each key can be assigned at most one value. HashMap implements the Map interface while SortedMap extends the Map interface and TreeMap implements the SortedMap interface.

The student list is an object of type Map. You can store ropes. The put method is used to insert items into the studentList. There are two records in “Peter” but it will only show one record. HashMap does not maintain the embedded order. It only prints the unique values.

Letters is an object of type Map. You can store ropes. The put method is used to insert elements to letters. There are two records in “B”, but it will only show one record. TreeMap does not maintain the inserted order. It only prints the unique values.

Difference Between Set and Map

Definition

A Set is an interface in the Collection hierarchy that cannot contain duplicate elements, while a Map is an interface that maps unique keys to values. This is the main difference between Set and Map.

Association with the collection interface

Set is an interface that extends the Collection interface while Map is a separate interface.

functionality

Functionality is also a big difference between Set and Map. The set helps store unique values, while the map interface represents a mapping between a key and a value.

conclusion

The main difference between Set and Map is that Set is a collection interface subtype while Map is not a collection interface subtype.

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