Why do we need public class in Java?

public is a Java keyword which declares a member’s access as public. Public members are visible to all other classes. … This helps with encapsulation and information hiding, since it allows you to change the implementation of a class without affecting the consumers who use only the public API of the class.

Is public class necessary in Java?

java file without a public class. Okay, so a java source file must have at least one public class and the file should be called “class-name.

Why do we use public for one class?

So the reason behind keeping one public class per source file is to actually make the compilation process faster because it enables a more efficient lookup of source and compiled files during linking (import statements).

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.

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What if there is no public class in Java?

java. the compiler does not complain if you have a java file with no public classes. But, since you are using the main method and trying to run the java file, your java file must have the same name as your java class.

Can we have a class without the public?

It’s not public unless you use the keyword. Default (without any keyword) visibility means that your class visible inside package where it defined. The default access level is different from public, protected and private – so a class is not by default public if you don’t add one of those three keywords.

What is Java public class?

public is a Java keyword which declares a member’s access as public. Public members are visible to all other classes. This means that any other class can access a public field or method. Further, other classes can modify public fields unless the field is declared as final .

How many public classes a Java file can have?

java file can contain only one public class. If you want these two classes to be public they have to be put into two .

Can we have two public classes in Java?

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.

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Can abstract classes be final?

No, An abstract class can’t be final because the final and abstract are opposite terms in JAVA. Reason: An abstract class must be inherited by any derived class because a derived class is responsible to provide the implementation of abstract methods of an abstract class.

Can we execute a class without a main method?

Yes You can compile and execute without main method By using static block.

What is the difference between public/private and protected in java?

Public members can be accessed from the child class of the same package. Private members cannot be accessed from the child class of the same package. Protected members can be accessed from the child class of the same package. Package members can be accessed from the child class of the same package.

Can a class be private in java?

Yes, we can declare a class as private but these classes can be only inner or nested classes. We can’t a top-level class as private because it would be completely useless as nothing would have access to it.

What is encapsulation explain?

Encapsulation is defined as the wrapping up of data under a single unit. It is the mechanism that binds together code and the data it manipulates. Another way to think about encapsulation is, it is a protective shield that prevents the data from being accessed by the code outside this shield.

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