The interface provides information class just act like dummy things - implementation of details.
The Collection interface (java.util.Collection) and Map interface (java.util.Map) are two main root interfaces of Java collection classes.
First of all, learn about collection Interfaces.
collection interface defines the most common methods which are applicable to any collection objects. In general, collection framework is considered as root interface of collection framework.
The collection is an interface which can be used to represent a group of individual objects as a single entity. Whereas, collections is a utility class present in java.util package to define several utility methods for collection objects.
if we want to represent a group of individual objects as a single entity where duplicates are allowed and insertion order is preserved then we should go for the list.
vector and stack were introduced in JDK 1.0 so they are also called legacy classes. But, Both were re-engineered in JDK 1.2 to implement list interface.
It is the child interface of the collection. If we want to represent a group of individual objects as a single entity where duplicates are not allowed and insertion order is not preserved then we should go for the set.
It is the child interface of the set. if we want to represent a group of individual objects as a single entity where duplicates are not allowed but all objects should be inserted according to some sorting order then we should go for the sorted set.
it is the child interface of the sorted set. it defines several methods for navigation purposes.
It is the child interface of the collection. If we want to represent a group of individual objects prior to processing then we should go for the queue.
All the above interfaces - collection, list, set, sorted set, Navigation set and queue, all were meant for representing a group of individual objects. But, if we want to represent a group of objects as key-value pairs then we should go for map interface.
Now let's have a look at Map
If we want to represent a group of individual objects as key-value pairs then we should go for Map.
First of all, learn about key-value pairs.
Here, RollNO is Key and Name is Value. If we want to access "Ravi" then we will call key - 101 and so on.
It is the child interface of Map. If we want to represent a group of key-value pairs according to some sorting order of keys then we should go for SortedMap.
It is the child interface of Sorted Map. It defines several utility methods for navigation purposes.
The Collection interface (java.util.Collection) and Map interface (java.util.Map) are two main root interfaces of Java collection classes.
There was no concept of collection framework before jdk 1.2
Hierarchy of Collection Framework
First of all, learn about collection Interfaces.
1. Collection
collection interface defines the most common methods which are applicable to any collection objects. In general, collection framework is considered as root interface of collection framework.
There is no concrete class which implements as root interface of collection framework.
Difference between collection and collections
The collection is an interface which can be used to represent a group of individual objects as a single entity. Whereas, collections is a utility class present in java.util package to define several utility methods for collection objects.
2. List
list is child interface of the collection.
if we want to represent a group of individual objects as a single entity where duplicates are allowed and insertion order is preserved then we should go for the list.
vector and stack were introduced in JDK 1.0 so they are also called legacy classes. But, Both were re-engineered in JDK 1.2 to implement list interface.
3. SET
It is the child interface of the collection. If we want to represent a group of individual objects as a single entity where duplicates are not allowed and insertion order is not preserved then we should go for the set.
Difference between List and set
4. SortedSet
It is the child interface of the set. if we want to represent a group of individual objects as a single entity where duplicates are not allowed but all objects should be inserted according to some sorting order then we should go for the sorted set.
5. Navigation set
it is the child interface of the sorted set. it defines several methods for navigation purposes.
It was introduced in jdk 1.6
6. Queue
It is the child interface of the collection. If we want to represent a group of individual objects prior to processing then we should go for the queue.
Queue concept was introduced in jdk 1.5
All the above interfaces - collection, list, set, sorted set, Navigation set and queue, all were meant for representing a group of individual objects. But, if we want to represent a group of objects as key-value pairs then we should go for map interface.
Now let's have a look at Map
7. Map
The map is not the child interface of the collection.
If we want to represent a group of individual objects as key-value pairs then we should go for Map.
First of all, learn about key-value pairs.
Here, RollNO is Key and Name is Value. If we want to access "Ravi" then we will call key - 101 and so on.
Both key and value are objects. Duplicates keys are not allowed but the value can be duplicated.
8. SortedMap
It is the child interface of Map. If we want to represent a group of key-value pairs according to some sorting order of keys then we should go for SortedMap.
9. NavigableMap
It is the child interface of Sorted Map. It defines several utility methods for navigation purposes.
It was introduced in jdk 1.6
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