Constructors in Java

Constructor Java Training in Chennai is a block of code in the program,constructor is same as method,constructor doesn’t have any return type where method has return type.Constructor name is same as class name

Advantages of constructor

When we use constructor at the time of writing Java application then we get following advantages.

1) It eliminates in placing default values.

2) It eliminates in calling ordinary methods.

Characters of constructor

If we want to use a constructor as a part of Java program then we have follow properties.

1) Constructor will be called by the JVM implicitly when the object is created.

2) Constructor Core Java Training in chennai name is most similar to class name.

3) Constructor will not have any return type even void also

( if we write any return type then it will be treated as "Ordinary Method".)

4) Constructor should not be static ( because of constructor calling each & every time when an object is created ).

5) Constructor of java never participates in inheritance process (Because every constructor is meant for initializing with their own data member but not data member of another class.

6)

a)If the access modifier of the constructor is private then an object of an corresponding Java Training Institute in chennai class can be created in the class context but not in other class context.

b) If the access modifier of the constructor not private then an object of the corresponding class can

be created both class context and in another class context.

Types Of Constructors:

Constructors are classified into three types,they are:

1)Default Constructor

2)No-arg Constructor

3)Parameterized Constructor

Default Constructor:

The default constructor is nothing but a simple constructor ,it is enclosed in the .class file ,Core Java Training in chennai the default constructor will automatically Included in the file.

When the user don’t include the default constructor,the source code will automatically enclosed the constructor to the .class file

Example of Default Constructor:

public class Hello {

  String name;

  //Constructor

  Hello(){

     this.name = "Beginners";

  }

  public static void main(String[] args) {

     Hello obj = new Hello();

     System.out.println(obj.name);

  }

}

No-arg Constructor:

No-arg constructor is defined as Constructor with no arguments.it is same as default constructor.Java Training in chennai

Example of no-arg Constructor:

class Demo

{

    public Demo()

    {

        System.out.println("This is a no argument constructor");

    }

    public static void main(String args[]) {

    new Demo();

    }

}

Parameterized Constructor:

Constructor with arguments Java Training Institute in chennai are known as parameterized constructor.

Example of Parameterized Constructor:

public class Employee {

  int empId;  

  String empName;  

   

  //parameterized constructor with two parameters

  Employee(int id, String name){  

      this.empId = id;  

      this.empName = name;  

  }

  void info(){

       System.out.println("Id: "+empId+" Name: "+empName);

  }

  

  public static void main(String args[]){  

Employee obj1 = new Employee(10245,"Chaitanya");  

Employee obj2 = new Employee(92232,"Negan");  

obj1.info();  

obj2.info();  

  }

}

Output:

Id: 10245 Name: Chaitanya

Id: 92232 Name: Negan