Java Object Construction Example Program

Java Constructor Example Program

import java.util.*;

/**

* This program demonstrates object construction.

*/

public class ConstructorTest

{

public static void main(String[] args)

{

// fill the staff array with three Employee objects

Employee[] staff = new Employee[3];

staff[0] = new Employee("Harry", 40000);

staff[1] = new Employee(60000);

staff[2] = new Employee();

// print out information about all Employee objects

for (Employee e : staff)

System.out.println("name=" + e.getName() + ",id=" + e.getId() + ",salary="

+ e.getSalary());

}

}

class Employee

{

// three overloaded constructors

public Employee(String n, double s)

{

name = n;

salary = s;

}

public Employee(double s)

{

// calls the Employee(String, double) constructor

this("Employee #" + nextId, s);

}

// the default constructor

public Employee()

{

// name initialized to ""--see below

// salary not explicitly set--initialized to 0

// id initialized in initialization block

}

public String getName()

{

return name;

}

public double getSalary()

{

return salary;

}

public int getId()

{

return id;

}

private static int nextId;

private int id;

private String name = ""; // instance field initialization

private double salary;

// static initialization block

static

{

Random generator = new Random();

// set nextId to a random number between 0 and 9999

nextId = generator.nextInt(10000);

}

// object initialization block

{

id = nextId;

nextId++;

}

}

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