CODEWITHSUNDEEP
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Tushar Monirul
Tushar Monirul

Reputation: 5064

what is the difference between `public class` and just `class`?

I have noticed that if I don't write public before a class it works same as like a public class. I can't understand why so? It should show an error when I don't declare a class as public, private or protected. But it works fine. What is the reason?

Upvotes: 61

Views: 124618

Answers (9)

Blocked
Blocked

Reputation: 351

For declarations of classes, only 2 keywords are available:

  • public . public class Student{//...}
  • private package(as default) class Note{//...} .It is visible only in it's package.

You can use private and protected only if you declare an member inside of a class. Example:

public class Student{
protected Note note;
}

Upvotes: 0

Asad
Asad

Reputation: 1837

There must be at most one public class per .java source file and the name of the file must match with this public class.

Upvotes: 3

Abdulrazaq
Abdulrazaq

Reputation: 21

A class not declared with any access modifier is automatically declared as DEFAULT at runtime With these the class is accessible that same package
But not any other package

Upvotes: 1

joe john
joe john

Reputation: 1

No a normal class and a public class don't work the same .A class without a access modifier such as public is automatically set to default access.(No, you can't give default as access explicitly). If you create a default access class inside a package then that class cannot be accessed outside that package but public class can be accessed even outside that package

Upvotes: 0

Morfidon
Morfidon

Reputation: 1528

It works the same only because you are working with just probably one file and in the same package.

If you have more than one package then you have the problem. The class that doesn't have "public" before the name of class cannot be created in another package. You cannot use its constructor. You just cannot access it outside of the package that the class was created in.

Upvotes: 1

The_301
The_301

Reputation: 851

If you don't give an access modifier it's by default package private access. The class is not accessible outside of the package. Ideally the JLS should've included a keyword for package access to avoid confusion and unintended consequences.

Something like,

default class Student{}

Upvotes: 0

AlexR
AlexR

Reputation: 115328

public, protected and private are access modifiers. Public means that the subject may be accessed by any class, protected by subclass, private by the class itself, no modifier means "package protected", so the subject may be accessed by classes from the same package.

Subject is class, method, member variable.

Upvotes: 49

Esteban Araya
Esteban Araya

Reputation: 29664

Classes are package private by default (as outlined here) so it's not behaving the same way. You just think it is because you haven't tried to consume your class from a different package.

Upvotes: 9

Jon Skeet
Jon Skeet

Reputation: 1500065

I have noticed that if don't write public before a class its works same as like a public class.

No it doesn't. Unless it's public, the class won't be visible to other code which isn't in the same package. The default accessibility (which can't be specified explicitly) is that a class (or other member) is only visible to other code within the same package.

You should read the Java Language Specification section 6.6 and the Java Tutorial (Controlling Access to Members of a Class) for more details.

Upvotes: 56

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