Why should there be only one public class in Java?

There can be only one public class in a java file because the name of java file is same as the name of public class. And obviously we can’t have a file with two different names.

Why can’t we have two public classes in Java?

As per java language specification, there can be only one public class in a file (. java) and file name should be same as public class name. If you want class B accessible in other placs, you may create a separate B. java file and move your Class B code to that file.

Can we have to public classes in one Java file?

Long story short: no, you can’t put two public classes in one file because the compiler wouldn’t be able to handle that correctly.

Does every Java program must have a public class?

In Java, every method must be contained in a class. That would imply that every program must have a at least one class.

Can a Java file have two public classes?

No, while defining multiple classes in a single Java file you need to make sure that only one class among them is public. If you have more than one public classes a single file a compile-time error will be generated.

Should java classes be in separate files?

It is technically legal to have multiple Java top level classes in one file. However this is considered to be bad practice (in most cases), and some Java tools may not work if you do this. The JLS says this: When packages are stored in a file system (§7.2.

Can one Java file have multiple classes?

Yes, we can have multiple classes in same java file. So, there is no chance to have two public classes in one file. If we want to access the methods, instances of the other classes we can just make their respective objects in the public file and simply access them.

Can you have 2 public class in java?

Does Java always need a class?

The answer to your question depends on what exactly you mean. Do you mean a class with the name ‘Main’? Then, no, there is no requirement for this at all. The only requirement that Java has, is that the signature of the method is correct.

Is it necessary to have a class in Java?

Java enforces OOP with a class system, so you may hear it referred to as a class-oriented language. While you do have to create a class, the question specifically asks if you have to create a class for your program and a main class to call it. The answer to that is “no”.

How many public classes can be in a package?

one public class
There are simple rules: 1) Only one public class can be defined in one . java file. But many . java file can exists in a package.

How many public classes can be declared in a java file?

The restriction is on there should be maximum one public class in a java file. If you would not declare any of the class as public in a java file, it treats the class as public in which you have define main method. But if you declare more then as a public class in a java file compiler gets confused.

Can there be more than one public class in a file?

There can be only one public class in a java file because the name of java file is same as the name of public class.And obviously we can’t have a file with two different names. It is how it has been designed and I am not sure if the reason is documented. But here is a good reason on why it is done that way.

Can we compile a java file with a different name than class?

yes, we can compile a java file with a different name than the class, provided that there should not be any public class in that file. If there is any public class in file then in that case you have to give that name as file name.

Do I need to mark a class as public in Java?

If you want a main method in the class to execute, then yes, you must keep a public class in your java file (and the name should match with the name of the file). If you want a class to be visible in the same package, but you don’t care about the outside of the package, then no need to mark the class as public.