18 Answers. Yes, it can. However, there can only be one public top-level class per . java file, and public top-level classes must have the same name as the source file.
How many public class you can have in a java source 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.
Why can’t we have multiple public classes in a java source 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.
Can we have two public classes in a java file explain with an example?
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.
How many classes are permitted within a single Java class file?
in single java file, we can define only one public class . because if you define any class as public then name of your class and name of saving java class file must be same.
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 I have multiple 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.
Can I have main methods for every class in a file?
Ans: Yes. You can have more than one method with the name main but different signature.
What are nested classes in java?
A nested class is a member of its enclosing class. Non-static nested classes (inner classes) have access to other members of the enclosing class, even if they are declared private. Static nested classes do not have access to other members of the enclosing class.
How many .class files are created in java?
java ” file has more than one class.
How many public classes can be in a package?
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 do I run a Java program with many classes?
Run by typing java classname. For example, java smtpClient. Note: If you are using multiple classes in your program you will need to compile all of the files and then run the program by using the classname of the class that contains your main method. You should see the output.
How do you call multiple classes in Java?
In general, Java has a main public class with a name that should match with the Java class file name and it calls other classes from this main class. The second approach is to write each class in different files and link them together with a package. In other words, all class files should be in the same class.
Can a Java program have 2 main methods?
Yes, you can have as many main methods as you like. You can have main methods with different signatures from main(String) which is called overloading, and the JVM will ignore those main methods. You can have one public static void main(String args) method in each class. Some people use those methods for testing.