What are the reference types in java

Reference Types in Java

Reference types are used in Java to store references to objects. They differ from primitive types, which store values ​​directly. There are the following reference types in Java:

Class object

A class object represents a class and can be used to create instances of that class.

Array object

Array object stores an ordered collection of elements of the same type.

Interface Object

The interface object represents an interface and can be used to implement the interface.

String object

String object stores an immutable sequence of characters.

Other objects

There are other reference types in Java that are used to represent objects for specific purposes, such as:

• Date object ( java.util.Date)
• Collection Framework Object (java.util.List, java.util.Map)
• Input/output stream objects (java.io.InputStream, java.io.OutputStream)

Reference types and basic types

Compared with basic types, reference types have the following characteristics:

• Reference types store references to objects, not the values ​​themselves.
• Reference type variables can point to null, which means no object is referenced.
• Objects of reference types can be created in the heap and automatically released by the garbage collector.
• Objects of reference types can be shared by passing by reference, while values ​​of basic types can be shared by passing by value.

When to use reference types

Reference types should be used in the following situations:

• When you need to store an object reference.
• When you need to store variable data structures.
• When you need to store objects with complex behavior.

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