Thursday, 12 October 2017

Constructor in Java


Explain Constructor In Java

"The constructor is a special method whose task initialize the data members of a class".

→ Class name and constructor name must be same.

→ It's a special kind of method.

→ They don't have return type not even void.

→ Constructor call automatically when an object is created.

→ They can't be inherited, through a derived class can call the base class constructor.

 Syntax:

   public class_name(args)
   {
              //Statement;
   }

There is 2 type of constructor available in java.

1) Default constructor 
2) Parameterized constructor

#1) Default constructor

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.

Class A

{
           int a;

           public A()

           {
                     a=10;

           }

 }

class demo

{
            public static void main(String args[])

            {

                  A obj=new A();

             }

}

#2) Parameterized constructor

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

public class Employee 
{

   int empId;
   String empName;
      
  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,"Chintan");
    Employee obj2 = new Employee(92232,"Nigam");
    obj1.info();
    obj2.info();
   }
}


 

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