CODEWITHSUNDEEP
javavariablesprivateprogram-entry-point
narancs
narancs

Reputation: 5294

Why can I access a private variable from main method?

package com.valami;

 public class Ferrari
 {
  private int v = 0;


  private void alam()
  {
   System.out.println("alam");
  }

  public Ferrari()
  {
   System.out.println(v);
  }



  public static void main(String[] args)
  {
   Ferrari f = new Ferrari();
   f.v = 5;
   System.out.println(f.v);
  }

 }

Hi all! I have one simple question.... WHY can I reach a private variable from the main method ? I know, I'm in the containing class, but it is main. I believed the main is NOT part of the class which is containing it... Then I would not to reach an private member, but I can....WHY? Please help...thx

Upvotes: 13

Views: 13888

Answers (8)

daisy ho
daisy ho

Reputation: 1

Since you have made the main method in the same class as the private attribute v, you can access it. Privates attribute or methods are accessible to its own class.

That is to say, if you moved the main method to another class, you cannot access anything that has a private modifier.

Upvotes: 0

Viktor
Viktor

Reputation: 486

Main is a part of you class, you have declared it inside your class :) What main is not is part of your object, it will not be any part of the objects you create from the class but it is still part of the class. This is correct for any static function as main is just a normal static function that the framework knows it should look for when the program is executed.

Upvotes: 6

Arjan Tijms
Arjan Tijms

Reputation: 38163

Classes can access the private instance variables of (other) objects of the same type.

The following is also possible

public class Foo {

    private int a;

    public void mutateOtherInstance(Foo otherFoo) {
        otherFoo.a = 1;
    }
}

You could argue if this is desirably or not, but it's just a rule of life that the JLS has specified this is legal.

Upvotes: 12

AbstractDissonance
AbstractDissonance

Reputation: 1

Because main is static and your class hasn't been instantiated.

e.g., you have no Ferrari object to access. You must create a Ferrari object then access it's members. static main is a special static function. You can think of it as sort of separate if you want. So if you moved your main method outside of Ferrari you would expect that you would have to create an instance of Ferrari to use it... same deal here.

Upvotes: -2

Benjamin Gale
Benjamin Gale

Reputation: 13177

The only special feature of the main method is it is used to tell the compiler where program execution should begin. Other than that it behaves just like any other class method and has access to private variables like any other class method.

Upvotes: 1

jk.
jk.

Reputation: 7686

As long as the private variable is in the same class as the main() method, then the main() method has access to it. In general, even static methods have access to private fields of instances of the same class.

Upvotes: 1

biziclop
biziclop

Reputation: 49744

Well, main() is part of the containing class. In fact, main() is exactly like every other method, except that you can start the JVM and tell it to run the main() method of a class from the command line.

Upvotes: 1

Femaref
Femaref

Reputation: 61437

The main method is in the class Ferrari and thus can access private variables, even if it's static.

Upvotes: 3

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