default constructor in java code example

Example 1: type of constructor in java

There are three types of constructors: 
Default, No-arg constructor and Parameterized.
  
If you do not implement any constructor in your class,
Java compiler inserts a default constructor into your code on your behalf.
This constructor is known as default constructor.
  
Constructor with no arguments is known as no-arg constructor

Constructor with arguments(or you can say parameters) is known as 
Parameterized constructor.

Example 2: java constructor

class Huso {
  public Huso() {
  	//constructor code about a huso
  }
}

Example 3: default constructor java

Default constructor is a constructor created by compiler; if user does not 
create a constructor in a class.
If user defines a constructor in a class then java compiler will not create 
default constructor.

Example 4: default constructor java

class NoteBook{
   /*This is default constructor. A constructor does
    * not have a return type and it's name
    * should exactly match with class name
    */
   NoteBook(){
      System.out.println("Default constructor");
   }
   public void mymethod()
   {
      System.out.println("Void method of the class");
   }
   public static void main(String args[]){
	/* new keyword creates the object of the class
         * and invokes constructor to initialize object
         */
	NoteBook obj = new NoteBook();
	obj.mymethod();
   }
}

Tags:

Java Example