How to Create Array of Objects in Java

In this section, we will learn how to create and initialize an array of objects in Java.

Array of Objects in Java

Java is an object-oriented programming language. Most of the work done with the help of objects. We know that an array is a collection of the same data type that dynamically creates objects and can have elements of primitive types. Java allows us to store objects in an array. In Java, the class is also a user-defined data type. An array that conations class type elements are known as an array of objects. It stores the reference variable of the object.

Creating an Array of Objects

Before creating an array of objects, we must create an instance of the class by using the new keyword. We can use any of the following statements to create an array of objects.

Syntax:

ClassName obj[]=new ClassName[array_length]; //declare and instantiate an array of objects

Suppose, we have created a class named Employee. We want to keep records of 20 employees of a company having three departments. In this case, we will not create 20 separate variables. Instead of this, we will create an array of objects, as follows.

Employee department1[20];
Employee department2[20];
Employee department3[20];

The above statements create an array of objects with 20 elements.

Let's create an array of objects in a Java program.

In the following program, we have created a class named Product and initialized an array of objects using the constructor. We have created a constructor of the class Product that contains product id and product name. In the main function, we have created individual objects of the class Product. After that, we have passed initial values to each of the objects using the constructor.

ArrayOfObjects.java

public class ArrayOfObjects
{
public static void main(String args[])
{
//create an array of product object 
Product[] obj = new Product[5] ;
//create & initialize actual product objects using constructor
obj[0] = new Product(23907,"Dell Laptop");
obj[1] = new Product(91240,"HP 630");
obj[2] = new Product(29823,"LG OLED TV");
obj[3] = new Product(11908,"MI Note Pro Max 9");
obj[4] = new Product(43590,"Kingston USB");
//display the product object data
System.out.println("Product Object 1:");
obj[0].display();
System.out.println("Product Object 2:");
obj[1].display();
System.out.println("Product Object 3:");
obj[2].display();
System.out.println("Product Object 4:");
obj[3].display();
System.out.println("Product Object 5:");
obj[4].display();
}
}
//Product class with product Id and product name as attributes
class Product
{
int pro_Id;
String pro_name;
//Product class constructor
Product(int pid, String n)
{
pro_Id = pid;
pro_name = n;
}
public void display()
{
System.out.print("Product Id = "+pro_Id + "  " + " Product Name = "+pro_name);
System.out.println();
}
}

Output:

Product Object 1:
Product Id = 23907   Product Name = Dell Laptop
Product Object 2:
Product Id = 91240   Product Name = HP 630
Product Object 3:
Product Id = 29823   Product Name = LG OLED TV
Product Object 4:
Product Id = 11908   Product Name = MI Note Pro Max 9
Product Object 5:
Product Id = 43590   Product Name = Kingston USB

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