Constructor in Java
Constructor in java is a special type of method that is used to initialize the object.
Java constructor is invoked at the time of object creation. It constructs the values i.e. provides data for the object that is why it is known as constructor.
Rules for creating java constructor
There are basically two rules defined for the constructor.
Types of java constructors
There are two types of constructors:
Java Default Constructor
Syntax of default constructor:
Example of default constructor
Bike is created
Rule: If there is no constructor in a class, compiler automatically creates a default constructor.
Q) What is the purpose of default constructor?
Default constructor provides the default values to the object like 0, null etc. depending on the type.
Example of default constructor that displays the default valuesTest it Now
0 null 0 null
Explanation:In the above class,you are not creating any constructor so compiler provides you a default constructor.Here 0 and null values are provided by default constructor.
Java parameterized constructor
Why use parameterized constructor?
Example of parameterized constructor
111 Karan 222 Aryan
Constructor Overloading in Java
Example of Constructor OverloadingTest it Now
111 Karan 0 222 Aryan 25
Difference between constructor and method in java
There are many differences between constructors and methods. They are given below.
Java Copy Constructor
There is no copy constructor in java. But, we can copy the values of one object to another like copy constructor in C++.
There are many ways to copy the values of one object into another in java. They are:
In this example, we are going to copy the values of one object into another using java constructor.
111 Karan 111 Karan
We can copy the values of one object into another by assigning the objects values to another object. In this case, there is no need to create the constructor.Test it Now
111 Karan 111 Karan
Ans:yes, that is current class instance (You cannot use return type yet it returns a value).
Yes, like object creation, starting a thread, calling method etc. You can perform any operation in the constructor as you perform in the method.