Creating Objects : New « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. New

1. Using the new keyword.
2. new is always followed by the constructor of the class.

For example, to create an Employee object, you write:

Employee employee = new Employee();

Here, 'employee' is an object reference of type Employee.

1. Once you have an object, you can call its methods and access its fields, by using the object reference.
2. You use a period (.) to call a method or a field.

For example:

objectReference.methodName
objectReference.fieldName

The following code, for instance, creates an Employee object and assigns values to its age and salary fields:

public class MainClass {

  public static void main(String[] args) {
    Employee employee = new Employee();
    employee.age = 24;
    employee.salary = 50000;
  }

}

class Employee {
    public int age;
    public double salary;
    public Employee() {
    }
    public Employee(int ageValue, double salaryValue) {
        age = ageValue;
        salary = salaryValue;
    }
}

When an object is created, the JVM also performs initialization that assign default values to fields.