Packages and Compilation Units - Quiz

1.	Which of the following are true about a Java source code file? Please select all the correct answers.
	A.	It must contain at least one `public` class or interface.
	B.	It must take the name of a class or interface that is declared within it.
	C.	It must end with the .java extension.
	D.	It must begin with a `package` statement.

2.	Which of the following are true about packages and importing? Please select all the correct answers.
	A.	If an `import` statement is used, it must be the first non-blank line of a source code file.
	B.	A package is used to define a separate naming context.
	C.	A package may contain more than one class or interface of the same name.
	D.	The `java.lang` package is automatically imported and does not need to be imported using an `import` statement.

3.	Suppose that the source code file `MyCode.java` contains the following source code. What errors are associated with this code? public class MyClass { } public interface MyInterface { } Please select all the correct answers.
	A.	`MyClass` should implement `MyInterface`.
	B.	The code does not have a `main()` method.
	C.	A public class or interface must be defined in a file with the same name plus the `.java` extension.
	D.	No more than one `public` class or interface may be in the same source code file.

4.	What is wrong with the following source code file? import java.util.*; package myPackage; class MyClass extends MyInterface { } interface MyInterface { } Please select all the correct answers.
	A.	Only one class or interface may be defined in a source code file.
	B.	At least one class or interface must be `public`.
	C.	A class cannot extend an interface.
	D.	The `package` statement should be the first non-blank line in the file.