JAVA

how to create a constructor in java

class Other{
    public Other(String message){
        System.out.println(message);
    }
}

class scratch{
    public static void main(String[] args) {
        Other method = new Other("Hey");
        //prints Hey to the console
    }
}

syntax of a constructor in java

public class MyClass {//this is an example of a class with a non default constructor  
    private int number = 0;

    public MyClass() {
    }

    public MyClass(int theNumber) {//this is the constructor
        //acces modifiers+constructor name(it needs to be the same as the class name)+parameters
        this.number = theNumber;
    }
}

what is constructor in java

A constructor is a special method used to initialize objects in java.
we use constructors to initialize all variables in the class 
when an object is created. As and when an object
is created it is initialized automatically with the help of 
constructor in java.
  
We have two types of constructors:
Default Constructor
Parameterized Constructor

public classname(){
}
public classname(parameters list){
}

different constructiors in java and what they do explained

public class Hello {
   String name;
   //Constructor
   Hello(){
      this.name = "BeginnersBook.com";
   }
   public static void main(String[] args) {
      Hello obj = new Hello();
      System.out.println(obj.name);
   }
}

java constructor example

class Main {
  private String website;
  // constructor
  Main() {
    website = "'softhunt.net'";
  }

  public static void main(String[] args) {

    // constructor is invoked while
    // creating an object of the Main class
    Main obj = new Main();
    System.out.println("Welcome to " + obj.website);
  }
}

Java Constructor

class Main {
  private String name;

  // constructor
  Main() {
    System.out.println("Constructor Called:");
    name = "Programiz";
  }

  public static void main(String[] args) {

    // constructor is invoked while
    // creating an object of the Main class
    Main obj = new Main();
    System.out.println("The name is " + obj.name);
  }
}

Constructors in Java

// Java Program to Illustrate Working of
// Parameterized Constructor
 
// Importing required inputoutput class
import java.io.*;
 
// Class 1
class Geek {
    // data members of the class.
    String name;
    int id;
 
    // Constructor would initialize data members
    // With the values of passed arguments while
    // Object of that class created
    Geek(String name, int id)
    {
        this.name = name;
        this.id = id;
    }
}
 
// Class 2
class GFG {
    // main driver method
    public static void main(String[] args)
    {
        // This would invoke the parameterized constructor.
        Geek geek1 = new Geek("adam", 1);
        System.out.println("GeekName :" + geek1.name
                           + " and GeekId :" + geek1.id);
    }
}