Java Array of Object

Array of objects is the collection of objects of the same class.

Normally we declare the multiple objects of a class just like normal variables as
Student s1,s2,s3 ....sn;

Before going to learn array of objects first learn about the array in java

Syntax

classname arrayName[] = new classname[dimension];

classname : is the name of class which is defined

dimension : is the size of array starting from index 0 to n

Example

Creating the array of 5 Objects of Student class as

Student s1[] = new Student[5];

This will create array of 5 objects of student class.

We need to allocate memory for every object as

Student s1[0] = new Student();
Student s1[1] = new Student();
Student s1[2] = new Student();
Student s1[3] = new Student();
Student s1[4] = new Student();

This can be done by using loops as below

for(int i=0;i<5;i++)
{
	s1[i] = new Student();
}

Example

Define a class Student having data members rollnumber,name,marks. accept and display detailes of 5 students.

import java.util.Scanner;
class Student
{
     Scanner sc;
     String name;
     int rollno;
     float marks;
     void getData()
     {
	 sc = new Scanner(System.in);
	 System.out.print("Enter name : ");
	 name = sc.next();
	 System.out.print("Enter roll no : ");
	 rollno = sc.nextInt();
	 System.out.print("Enter marks : ");
	 marks = sc.nextFloat();
     }
     void display()
     {
	 System.out.println("\nName : "+name);
	 System.out.println("Roll no: "+rollno);
	 System.out.println("Marks : "+marks);
     }
     public static void main(String args[])
     {
	 int i;
	 Student s1[] = new Student[5];
	 for(i=0;i<2;i++)
	 {
	      s1[i] = new Student();
	      s1[i].getData();
	 }
	 System.out.println("\nStudent detailes are");
	 for(i=0;i<2;i++)
	      s1[i].display();
      }
}
	

Output