Could someone tell me why instructor refused my answer?

I am being asked this question:

What are the two of the three cases where a class can use other classes without requiring import statements?

i answered with this:

) By referring to the class by package name.

2) Importing them through the source file.

He told me it was wrong but I am not sure what other cases there would be.

What do you mean by importing through source file?

Class.forName(...)

It is a question I always ask in interviews.

WP

An import statement is not required if the other class resides in the same package.

Well, I guess another question would be what are the 3 cases?

Actually there are 4
a) same package
b) inner class (which is technically in same package.. so above 2 can be considered the same)
c) Reflection
d) explicitly using the package name with the class name

Jayesh A Lalwani wrote:Actually there are 4
a) same package
b) inner class (which is technically in same package.. so above 2 can be considered the same)
c) Reflection
d) explicitly using the package name with the class name

Considering that this is likely for a beginner's class, I would safely rule out reflection and the inner classes response as the answers the instructor is looking for. The third one is likely for the case were the class to be imported resides in the java.lang package.

Henry

Well, since b is completely implied by a, b is completely unnecessary. Similarly, even if you use reflection, you will need to use the full package name, so it's really just another case of a. The use of the java.lang package is the only other option that makes any sense.

Ahh yes, forgot about java.lang

I thought when he said "importing them through source file", I thought he was going for inner classes. Could be wrong. That is why I asked

Jayesh A Lalwani wrote:d) explicitly using the package name with the class name

technically, it is an import . the work is done by compiler.

Seetharaman Venkatasamy wrote:

Jayesh A Lalwani wrote:d) explicitly using the package name with the class name

technically, it is an import . the work is done by compiler.

But it is "without an import statement".

I can imagine that when the question is:

kenny gill wrote:What are the two of the three cases where a class can use other classes without requiring import statements?

and you answer:

kenny gill wrote:2) Importing them through the source file.

that your instructor refuses the answer, because that answer is exactly what he excluded in the question.

Static class don't require import.

Vinod Tiwari wrote:Static class don't require import.

I assume you mean nested class here? (Since you can't have top-level static classes). It's not actually true though - the cases where you need to import a static nested class are exactly the same as where you need to import any other class. That is, it's in a different package (other than java.lang), and you're not using the fully-qualified name.