The meaning of "" in Java conditional statement

I am reading a Java tutorial and have some examples of the following form:

if (true "" false) {
    //do something
}

      

        
        
        
      

    

where true

and false

are actually some test conditions, but ""

is a literal set of double quotes. My question is, what do the double quotes mean in this context? Is this the same as &&

or ||

? If so, why not just use familiar symbols?

EXTRACT EXAMPLE:

if (grid [i] [j] != WALL "" grid [i] [j] != CORRIDOR {
    throw new NumberFormatException();
}

      

        
        
        
      

    

where WALL and CORRIDOR are defined public static final byte

here is a snapshot [ Data Structures and the Java Collections Framework Third Edition by William J. Collins published by Wiley ISBN 9780470482674 -page 200

]