File separator allowed within java.io.File

Question

Found a confusing question while learning about file separators

Suppose that the file c:\book\java exists. Which of the following lines of code creates an object that represents the file? (Choose all that apply.)

1. new File("c:\book\java"); 2. new File("c:\\book\\java"); 3. new File("c:/book/java"); 4. new File("c://book//java"); 5. None of the above

the book (assumig a dos based file system) says that

2. & 3. are right answer

2. is correct because Java requires a backslash to be escaped with another backslash.
3. is also correct because Java will convert the slashes to the right one when working with paths..

• Can 4 also be correct by this logic?
• and when i change to mac/linux file system - what should be the answer ? (update: we are only creating a file object - whether it makes sense is not the question here - the question is which of these will finally return the path shown above)

Answer 1

Can 4 also be correct by this logic?

Given that the question is

Suppose that the file c:\book\java exists. Which of the following lines of code creates an object that represents the file? (Choose all that apply.)

1. new File("c:\book\java");
2. new File("c:\book\java");
3. new File("c:/book/java");
4. new File("c://book//java");
5. None of the above

2 and 3 are obviously correct. So, does the File object in 4 "create an ojbect that represents the file"?

Yes it does.

Assuming C:\book\java exists, this code

public static void main( String[] args ) throws IOException
{
    File f = new File( args[ 0 ] );
    System.err.printf( "args[0]: %s\n", args[ 0 ] );
    System.err.printf( "Path: %s\n", f.getCanonicalPath() );
}

produces this output:

args[0]: C://book//java
Path: C:\book\java

So new File( "C://book//java" ) most definitely "creates an object that represents the file" and is also a correct answer.

Any argument that it does not is literally incorrect. The question is whether or not the string "creates an object that represents the file". C://book//java demonstrably does exactly that.