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Table of contents
1.
Introduction 
2.
What is an Instantiation in Java?
2.1.
What is an Object?
2.2.
What is class
3.
Syntax for Instantiation in Java
4.
Instantiation of an Object in Java
5.
Creating Instances
5.1.
By using the New Keyword
5.1.1.
For example
5.2.
Java
5.2.1.
Output
5.3.
By using Static Factory Method
5.3.1.
For example
5.4.
Java
5.4.1.
Output
6.
Difference between instantiation and initialization
7.
Advantages of Instantiation
8.
Disadvantages of Instantiation
9.
Frequently Asked Questions
9.1.
What is the purpose of instantiation in Java?
9.2.
In Java, can we prevent instantiation and how?
9.3.
In Java, during instantiation, what happens?
9.4.
Can we prevent a class from instantiation, and how?
10.
Conclusion
Last Updated: Mar 27, 2024
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Instantiation in Java

Author Monika Yadav
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Introduction 

Hello Ninjas, Do you know about Instantiation in Java? If not, then don’t worry. You are at the right place. In this blog, we will discuss the Instantiation In Java along with its advantages and disadvantages, and much more. So for what we are waiting for, Let’s get started with Instantiation in Java.

instantiation in java

What is an Instantiation in Java?

Instantiation in Java is the process of creating a new instance of a class. The new class is an object that can be used to store data and perform operations. To create a new instance of a class, we can use the "new" keyword followed by the class name and arguments  which the class constructor requires. 

What is an Object?

An object in Java represents a real-world entity or concept. It is an instance of a class with its own attributes and methods.

Also read, Swap Function in Java

What is class

A class is defined as a group of objects. Objects which have common properties. It is a blueprint from which objects are created. It is a logical entity and can't be physical.

In Java a class can contain:

  • Fields
     
  • Methods
     
  • Constructors
     
  • Blocks
     
  • Nested class and interface


Read about Classes and Objects in Java in detail.

Syntax for Instantiation in Java

ClassName objName = new ClassName();  


Let’s take an example for better understanding: To create a new instance of the "Person" class with a name of "Ninja" and an age of 20:

Person ninja = new Person("Ninja", 20);
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Instantiation of an Object in Java

Creating the object of a class in Java is called Instantiation. 

The initial memory space of an object is then occupied and a reference is then returned Object instantiation is provided by the blueprint of the class and an unlimited number of class objects are created for representing user-defined data such as lists. 

Creating Instances

We can create an object in various ways:

  • Using a new keyword.
     
  • Using the newInstance () method of the class.
     
  • Using the newInstance() method of the Constructor class.
     
  • Using Object Serialization and Deserialization.
     
  • Using the clone() method.
     

Mainly there are two ways by which we can create instances:

  • By using the new Keyword
  • By using Static Factory Method

Lets understand them in brief

By using the New Keyword

In Java, for class instantiating, a new keyword is used. Instantiation can be defined as the process of constructing a class object. An object is also known as the instance of a Java class. An instance of a class in Java is created using the new keyword.

ClassName objectName = new ClassName();
 

For example

  • Java

Java

class Solution {
String course;
int marks;

//Constructor
public Solution(String course, int marks) {
this.course = course;
this.marks = marks;
}
}

//Main class
public class Main {
public static void main(String[] args) {
Solution ninja = new Solution("Neha", 95);
System.out.println("Course: " + ninja.course);
System.out.println("Marks: " + ninja.marks);
}
}

Output

Output

By using Static Factory Method

The other method to instantiate a class is the static factory method. A static method that returns an instance of the class can be provided as a public static factory method by a class. 

For example

  • Java

Java

class Solution {
String name;
int subject;

//Constructor
private Solution(String name, int subject) {
this.name = name;
this.subject = subject;
}

public static Solution createSolution(String name, int subject) {
return new Solution(name, subject);
}
}

//Main class
public class Main {
public static void main(String[] args) {
Solution solution = Solution.createSolution("Neha", 5);
System.out.println("Name: " + solution.name);
System.out.println("Subject: " + solution.subject);
}
}

Output

Output

Difference between instantiation and initialization

Aspect Instantiation Initialization
Definition The process of creating a new instance of a table by allocating memory and setting up data structures. The process of setting the initial values of the table's elements.
Occurrence  Occurs when a program creates a new table object. Occurs after the table has been instantiated, but can also occur as part of the instantiation process.
Purpose Creates a new table object in memory. Sets the initial values of the table's elements.
Activities involved Allocating memory for the table, setting up data structures. Assigning default values, copying values from another table, or reading values from a file or user input.
Importance Necessary for a program to use a table object. Optional, but often required for the correct functioning of the program.
Example my_table = Table() creates a new empty table object my_table.initialize_from_file('data.csv') sets the initial values of my_table by reading data from a file.

Advantages of Instantiation

Instantiation in Java can have many advantages. Some of the possible advantages are the following:
 

  1. Object-oriented programming: In object-oriented programming, there is a concept of Instantiation. Instantiation is the primary programming paradigm in the java programming language. By creating objects through instantiation, Java programs can leverage the benefits of encapsulation, inheritance, and polymorphism.
     
  2. Encapsulation: Instantiation allows programs in Java to encapsulate data and behaviour within one object, which can improve program organization, reduce code duplication, and improve maintainability.
     
  3. Code reuse: In Java, programs can reuse code which already exists, rather than recreate functionality each time. This advantage of instantiation helps to reduce development time and improve code quality.
     
  4. Improved modularity: Instantiation can help Java programs achieve improved modularity by breaking down complex functionality into smaller, more manageable objects.
     
  5. Improved performance: Instantiation can actually improve performance. If the objects are created and reused efficiently. Let’s take an example for better understanding object pooling or caching can help to reduce the overhead associated with creating and destroying objects.
     

Also see, Duck Number in Java and Hashcode Method in Java

Disadvantages of Instantiation

Instantiation in Java can have disadvantages. Some of the  possible disadvantages of instantiation in Java are:
 

  1. Memory consumption: In Java, instantiation involves the allocation of memory for a new object, which can consume memory if the object is large or if many objects are created.
     
  2. Performance overhead: Instantiation in Java is a time-consuming operation.  Especially when the object being created requires complex initialization. Due to this reason, the overall performance of the whole program can be affected.
     
  3. Inefficient object reuse: The creation of a new object for every user can be inefficient. If the object is created and destroyed frequently. In these types of cases, object pooling or object recycling techniques can be used to reuse existing objects rather than create new ones each time.
     
  4. Object creation and destruction costs: In Java, Instantiation involves both object creation and object destruction costs. When an object is not required, it must be garbage collected, which can also add overhead to the program.
     
  5. Difficulty in testing: Instantiation in Java can make testing more difficult. If the objects have complex dependencies or require significant setup. In such cases, dependency injection may be necessary to simplify testing and improve testability.

 

Must Read Type Conversion in Java

Frequently Asked Questions

What is the purpose of instantiation in Java?

Instantiation in Java is the process of creating an object from a class. It allows you to allocate memory and initialize the attributes of an object, making it usable within your program to represent real-world entities or concepts.

In Java, can we prevent instantiation and how?

Yes, we can prevent instantiation in Java by using a static class to contain methods that are not associated with a particular object. 

In Java, during instantiation, what happens?

In Java, instantiation is used to create new instances of objects that will be utilized in the program. It creates an object in Java with the keyword “ new” for initializing the class object

Can we prevent a class from instantiation, and how?

Yes, we can prevent a class from instantiation by making a class non-instantiable. This can happen by making the constructor of the class private just by putting the private keyword before the class name.

Conclusion

We hope this article helped you understand Instantiation in Java. We have also discussed the Introduction, the difference between Instantiation and Initialization, and the advantages and disadvantages. You can also find out some related articles on our platform like:

Abstract Class and Methods in Java

Why is Java Platform Independent

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