What is constructor in Java

 Constructor.Are you confused about it . don't worry . Ok let's see the        code

public class Students {
    String name;
    int age;
  

    }

    public static void main(String[] args) {
   // write your code here\
        var s1=new Students();
        var s2=new Students();
    }

} 

ok  now I ask s1 " what is your name and your age ". It will tell My name is null and my age is 0. then I ask s2" what is your name and your age ". it will tell "My name is null and my age is 0."

Oh my god I am confused 

here you must know 

name and age are instance variables.Instance variables have default values. For numbers, the default value is 0, for Booleans it is false, and for object references it is null. Values can be assigned during the declaration or within the constructor

Here is the solution,

ok now we are moving on our  chapter  

Constructor 

Here we have added code  

Students(String name,int age)

{

    this.name=name;

    this.age=age;

}

this is constructor

don't panic . i will explain,

first you have to know 

Students s1=new Students();

here the new keyword is going to create an object and that time JVM also provides value for name as null and age as0.Students().This means calling the constructor hence it is going to initialize the object this is we called constructor .

 you can see this.name=name

here this  means current object.

so  when I create an object like 

Students s1=new Students("karan",22);

it set the name as "karan"

and set the age 22

so the constructor initializes the object.

so I think you might understand the constructor usage 

so what are the conditions we should follow to create constructor

• Constructor name must be the same as its class name.
• ok you can see I create constructor name Students . it is also class name.

• A Constructor must have no explicit return type.

    * if I put return type is it working?   sure but not a constructor . it is going to work as a method if you don't believe plz check it.

• A Java constructor cannot be abstract, static, final, and synchronized.
•  so can I put public in front of constructor . yaa sure when we put public .it will  work anywhere

OK now I ask one question 

 if I  don't create constructor , can I create objects? any one can help to create constructor ?

Do you have any  answer?????? 

Think it 

5

4

3

2

1

sure compiler will help you. compiler knows that you are an innocent programmer, that's why the compiler will create a default constructor for you at the time of compilation when you don't create any constructor. if you create any constructor then the compiler know that  he  has enough knowledge about constructor that why it doesn't create constructor 

So you know the truth , every class in java should have the constructor.

Now add some masalA!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

please give synatax of default constructor

yaaa sure

class Students

{

    Students()

    {

    super();

    }

}

Default construct contains only one line ,

.