How much Unicode knowledge do I need for the exam?

I know this:
Unicode representation of a character is indicated by a leading "\u" followed by a four digit hexidecimal number.
I know the range for characters is \u000 through \uffff.
What else do I need to know about Unicode for the exam?
[ April 23, 2002: Message edited by: Joshua White ]

And learn about \u000a or \u000d.
BTW, remember that,
"UTF8 encoding schema is used by the JVM internally for storing identifiers"
Jamal

Hello Joshua,
The reading of JLS 3 gives information about the use of Unicode in Java. Especially sections 1, 2, 3 , 10.4, 10.5 and 10.6
I think the most interesting thing to do is using the search engine to see others questions on the topic. And I will help with any concrete doubt in the JLS or posts.

[ April 23, 2002: Message edited by: Jose Botella ]
[ April 23, 2002: Message edited by: Jose Botella ]

This is a program that shows several points regarding Unicode in JLS 3

public class UnicodeInJava 
{    public static void main(String[] args)
     { 
        //Where Unicode is allowed?
        System.out.println("\u0456");
        System.out.println('\u0456');
        int \u0456dentifier = 0;// \u0456 = i in the Cyrillic alfabet
        //  \u0456
        /*  \u0456
        All of the above are ok because Unicode is allowed within comments, content for character and string literals,
        and identifiers. But ...
        */
        /*   int identifier2 = 0; compiler error, int is a reserved word, it must be formed only by ASCII.
        JEdit allowed me writting an i character (the i in int) of the Cyrillic alfhabet (\u0456) that looks like an ASCII i
        but obviously it is not i.
        */
        // JLS 3.2 The longest possible translation is performed in each step
        int a = 2, b = 1;
        // System.out.println(a--b); Compiler error, this is parsed as a, --,  b, which cannot compile because an operator
        //is missing between the result of a-- and b. Eventhough the compiler could have parsed a - - b, which is legal
        System.out.println(a - - b); //ok
        //The number of \ counts: a \ escapes the following character as JLS 3.10.6 specifies.
        System.out.println("\\"); // prints \  , we are escaping the second \
        // System.out.println("\"); Compiler error, we are not escaping \, but the last "
        //System.out.println('\');  Compiler error, we are not escaping \, but the last '
        //System.out.println("\z");// We cannot escape z, only the characters especified in JLS 3.10.6
        System.out.println("\\\\"); // prints \\, we are escaping the second and fourth \
        System.out.println("\\u0065 "); // prints \u0065, escaping the second \ prevents it from being part of a \u0065 Unicode char 
        System.out.println("\u0065\\\u0065");//  prints e\e
        
        // any number of u are allowed:
       System.out.println('\uuuuuuuuuuuuuuuuu0065');// This is still one character. Only one character is allowed in a Java char.
      // System.out.println('\\u0065'); Compiler error, escaping the second \, yields \, u, 0, 0, 6 and 5 chars. Too many for a char.
      
      // JLS 3.3 Unicode escapes:"If an eligible \ is followed by u, or more than one u, and the last u is not followed by four 
      //hexadecimal digits, then a compile-time error occurs."
      //This is true even within a comment:
      // \u1111     To see the compile errors just delete a digit
      /* \u1111
      */
      
      /* The unicode characters \u000d and \u000a cannot occur within simple or double quotes, even after // they yields 
      a compile error. However they can occur within multiple-line comments    
      */
       /* System.out.println("\u000d");         ok
            System.out.println(\u000a);             ok
       */
      //A character resulting from the Unicode translation (JLS 3.2.1) doesn't participate in further Unicode translations:
      System.out.println("\u005ctHello");//prints TABHello. \u005c is \ , resulting in \t, that is a  horizontal tab. 
      //This Lexical translation, JLS 3.2.1 , happens earlier than the consideration of Unicode escapes in strings and chars JLS 3.10.6
      //But...
      // System.out.println("\u005cu009Hello"); Compiler error. The \ resulting from the translation \u005c --> \ ,  doesn't 
      //participate in the translation \u0009 --> \t. Thus the result is \u0009Hello. This illegal as JLS 3.10.6 states: 
      //"It is a compile-time error if the character following a backslash in an escape is not an ASCII b, t, n, f, r, ", ', \, 0, 1, 2, 3,
      // 4, 5, 6, or 7. The Unicode escape \ u is processed earlier (�3.3)."
     
      
    }
}