when to use constructors

U need not to write a constructor until unless u want to send parameters to it. By default u will be having a default constructor which will take no arguments.

The purpose of the constructor is to create an object of a class. Constructors have the name same as the class name.

Ex

public class Student
{
     //constructor
         public Student() 
         {
         }
}

U can write the initial process in the constructor that should be executed when ever the object was created.

U can write ur own constructors to a class with different which will take different arguments (constructor overloading)