Constructor

A constructor in Java is a special method that is used to initialize objects.
The constructor is called when an object of a class is created.
It can be used to set initial values for object attributes

Example:-
// Create a Main class public class Main { int x; // Create a class attribute // Create a class constructor for the Main class public Main() { x = 5; // Set the initial value for the class attribute x } public static void main(String[] args) { Main myObj = new Main(); System.out.println(myObj.x); // Print the value of x } } // Outputs 5

Note that the constructor name must match the class name, and it cannot have a return type (like void).
Also note that the constructor is called when the object is created.
All classes have constructors by default: if you do not create a class constructor yourself, Java creates one for you.
However, then you are not able to set initial values for object attributes.

Constructor Parameters
Constructors can also take parameters, which is used to initialize attributes.
The following example adds an int y parameter to the constructor.
Inside the constructor we set x to y (x=y).
When we call the constructor, we pass a parameter to the constructor (5), which will set the value of x to 5

public class Main { int x; public Main(int y) { x = y; } public static void main(String[] args) { Main myObj = new Main(5); System.out.println(myObj.x); } } // Outputs 5